diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000000..1fe1b00e4f
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+.idea/
+node_modules/
diff --git a/output.txt b/output.txt
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/cli/args.js b/src/cli/args.js
index 8283f7f7aa..9d289056bc 100644
--- a/src/cli/args.js
+++ b/src/cli/args.js
@@ -1,5 +1,15 @@
 const parseArgs = () => {
-    // Write your code here 
+  const outputArray = [];
+
+  for (let index = 2; index < process.argv.length; index += 2) {
+    const key = process.argv[index].slice(2);
+    const value = process.argv[index + 1];
+
+    outputArray.push(`${key} is ${value}`);
+  }
+
+  const outputSeparator = ', ';
+  console.log(outputArray.join(outputSeparator))
 };
 
-parseArgs();
\ No newline at end of file
+parseArgs();
diff --git a/src/cli/env.js b/src/cli/env.js
index fe4aa4a8df..56f5cdc5e9 100644
--- a/src/cli/env.js
+++ b/src/cli/env.js
@@ -1,5 +1,17 @@
 const parseEnv = () => {
-    // Write your code here 
-};
+  const prefix = 'RSS_'
 
-parseEnv();
\ No newline at end of file
+  const allEnvVariables = process.env
+  const suitableVariables = []
+
+  for (const [key, value] of Object.entries(allEnvVariables)) {
+    if (key.startsWith(prefix)) {
+      suitableVariables.push(`${key}=${value}`)
+    }
+  }
+
+  const outputSeparator = '; '
+  console.log(suitableVariables.join(outputSeparator));
+}
+
+parseEnv()
diff --git a/src/cp/cp.js b/src/cp/cp.js
index 4a87b98c55..258690d285 100644
--- a/src/cp/cp.js
+++ b/src/cp/cp.js
@@ -1,6 +1,17 @@
+import { spawn } from 'child_process';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+
 const spawnChildProcess = async (args) => {
-    // Write your code here
+  const childProcessCodePath = path.resolve(__dirname, './files/script.js');
+  const childProcess = spawn('node', [childProcessCodePath, ...args]);
+
+  process.stdin.pipe(childProcess.stdin);
+  childProcess.stdout.pipe(process.stdout);
 };
 
-// Put your arguments in function call to test this functionality
-spawnChildProcess( /* [someArgument1, someArgument2, ...] */);
+spawnChildProcess(  ['arg1', 'arg2']);
diff --git a/src/fs/copy.js b/src/fs/copy.js
index bd17fe3991..35f0d6a3fe 100644
--- a/src/fs/copy.js
+++ b/src/fs/copy.js
@@ -1,5 +1,25 @@
+import fs from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const copy = async () => {
-    // Write your code here 
-};
+  const sourcePath = path.resolve(__dirname, './files');
+  const destinationPath = path.resolve(__dirname, './files_copy');
+
+  if (!fs.existsSync(sourcePath) || fs.existsSync(destinationPath)) {
+    throw new Error('FS operation failed');
+  }
+
+  await new Promise(resolve => {
+    fs.mkdir(destinationPath, {}, resolve);
+  });
+
+  await new Promise(resolve => {
+    fs.cp(sourcePath, destinationPath, { recursive: true}, resolve);
+  });
+}
 
 await copy();
diff --git a/src/fs/create.js b/src/fs/create.js
index 8d18cf9fc2..5062eb8899 100644
--- a/src/fs/create.js
+++ b/src/fs/create.js
@@ -1,5 +1,19 @@
+import fs from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const create = async () => {
-    // Write your code here 
+    const fileContent = 'I am fresh and young';
+    const filePath = path.resolve(__dirname, './files/fresh.txt');
+
+    if (fs.existsSync(filePath)) {
+        throw new Error('FS operation failed');
+    }
+
+    await fs.promises.writeFile(filePath, fileContent, { encoding: 'utf-8' });
 };
 
-await create();
\ No newline at end of file
+await create();
diff --git a/src/fs/delete.js b/src/fs/delete.js
index 4718dbc4c5..b19458a471 100644
--- a/src/fs/delete.js
+++ b/src/fs/delete.js
@@ -1,5 +1,18 @@
+import fs from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const remove = async () => {
-    // Write your code here 
+  const filePathToDelete = path.resolve(__dirname, './files/fileToRemove.txt');
+
+  if (!fs.existsSync(filePathToDelete)) {
+    throw new Error('FS operation failed');
+  }
+
+  fs.rmSync(filePathToDelete);
 };
 
-await remove();
\ No newline at end of file
+await remove();
diff --git a/src/fs/files/fileToRemove.txt b/src/fs/files/fileToRemove.txt
index 43e64cd45c..568ad5c5d8 100644
--- a/src/fs/files/fileToRemove.txt
+++ b/src/fs/files/fileToRemove.txt
@@ -1 +1 @@
-How dare you!
\ No newline at end of file
+How dare you
diff --git a/src/fs/files/fresh.txt b/src/fs/files/fresh.txt
new file mode 100644
index 0000000000..205d704cb7
--- /dev/null
+++ b/src/fs/files/fresh.txt
@@ -0,0 +1 @@
+I am fresh and young
\ No newline at end of file
diff --git a/src/fs/list.js b/src/fs/list.js
index c0a83dea15..91b97aa999 100644
--- a/src/fs/list.js
+++ b/src/fs/list.js
@@ -1,5 +1,24 @@
+import fs from 'fs'
+import path from 'path'
+import {fileURLToPath} from 'url'
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const list = async () => {
-    // Write your code here 
-};
+  const folderPath = path.resolve(__dirname, './files/')
+
+  if (!fs.existsSync(folderPath) || !fs.lstatSync(folderPath).isDirectory()) {
+    throw new Error('FS operation failed');
+  }
+
+  const files = await new Promise(resolve => {
+    fs.readdir(folderPath, (error, files) => {
+      resolve(files);
+    });
+  });
+
+  console.log(files);
+}
 
-await list();
\ No newline at end of file
+await list();
diff --git a/src/fs/read.js b/src/fs/read.js
index 52c78cc6ee..764736beac 100644
--- a/src/fs/read.js
+++ b/src/fs/read.js
@@ -1,5 +1,19 @@
+import fs from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const read = async () => {
-    // Write your code here 
+  const filePath = path.resolve(__dirname, './files/fileToRead.txt');
+
+  if (!fs.existsSync(filePath) || !fs.lstatSync(filePath).isFile()) {
+    throw new Error('FS operation failed');
+  }
+
+  const content = await fs.promises.readFile(filePath, { encoding: 'utf-8' });
+  console.log(content);
 };
 
-await read();
\ No newline at end of file
+await read();
diff --git a/src/fs/rename.js b/src/fs/rename.js
index 2bb99ecdb5..80be1467f2 100644
--- a/src/fs/rename.js
+++ b/src/fs/rename.js
@@ -1,5 +1,19 @@
+import fs from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const rename = async () => {
-    // Write your code here 
+  const sourcePath = path.resolve(__dirname, './files/wrongFilename.txt');
+  const resultPath = path.resolve(__dirname, './files/properFilename.md');
+
+  if (!fs.existsSync(sourcePath) || fs.existsSync(resultPath)) {
+    throw new Error('FS operation failed');
+  }
+
+  fs.renameSync(sourcePath, resultPath);
 };
 
-await rename();
\ No newline at end of file
+await rename();
diff --git a/src/hash/calcHash.js b/src/hash/calcHash.js
index 450f8f72e2..34cd4afe7f 100644
--- a/src/hash/calcHash.js
+++ b/src/hash/calcHash.js
@@ -1,5 +1,33 @@
+import { createHash } from 'crypto';
+import fs from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const calculateHash = async () => {
-    // Write your code here 
+  const filePath = path.resolve(__dirname, './files/fileToCalculateHashFor.txt');
+
+  const fileContent = await new Promise((resolve) => {
+    let data = '';
+
+    const stream = fs.createReadStream(filePath, {encoding: 'utf8'});
+
+    stream.on('data', part => {
+      data += part.toString();
+    });
+
+    stream.on('close', () => {
+      resolve(data);
+    });
+  });
+
+  const hash = createHash('sha256');
+  hash.update(fileContent);
+  const hashedValue = hash.digest('hex');
+
+  console.log(hashedValue);
 };
 
-await calculateHash();
\ No newline at end of file
+await calculateHash();
diff --git a/src/modules/esm.mjs b/src/modules/esm.mjs
new file mode 100644
index 0000000000..d448e0295f
--- /dev/null
+++ b/src/modules/esm.mjs
@@ -0,0 +1,45 @@
+import path from 'path';
+import {createRequire} from 'module';
+import {fileURLToPath} from 'url';
+import {release, version} from 'os';
+import {createServer as createServerHttp} from 'http';
+import './files/c.js';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+const random = Math.random();
+
+let unknownObject;
+
+const require = createRequire(import.meta.url);
+if (random > 0.5) {
+  unknownObject = require('./files/a.json');
+} else {
+  unknownObject = require('./files/b.json');
+}
+
+console.log(`Release ${release()}`);
+console.log(`Version ${version()}`);
+console.log(`Path segment separator is "${path.sep}"`);
+
+console.log(`Path to current file is ${__filename}`);
+console.log(`Path to current directory is ${__dirname}`);
+
+const myServer = createServerHttp((_, res) => {
+  res.end('Request accepted');
+});
+
+const PORT = 3000;
+
+console.log(unknownObject);
+
+myServer.listen(PORT, () => {
+  console.log(`Server is listening on port ${PORT}`);
+  console.log('To terminate it, use Ctrl+C combination');
+});
+
+export {
+  unknownObject, myServer
+};
+
diff --git a/src/streams/read.js b/src/streams/read.js
index 52c78cc6ee..30cf6460a1 100644
--- a/src/streams/read.js
+++ b/src/streams/read.js
@@ -1,5 +1,31 @@
+import {createHash} from 'crypto';
+import fs from 'fs';
+import path from 'path';
+import {fileURLToPath} from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const read = async () => {
-    // Write your code here 
+  const filePath = path.resolve(__dirname, './files/fileToRead.txt');
+
+  const data = await new Promise(resolve => {
+    const stream = fs.createReadStream(filePath);
+    let fileData = '';
+
+    stream.on('readable', () => {
+      let chunk;
+
+      while (null !== (chunk = stream.read(1))) {
+        fileData += chunk;
+      }
+    });
+
+    stream.on('end', () => resolve(fileData));
+  });
+
+
+  process.stdout.write(data);
 };
 
-await read();
\ No newline at end of file
+await read();
diff --git a/src/streams/transform.js b/src/streams/transform.js
index 315fc6597f..6b31a8e51a 100644
--- a/src/streams/transform.js
+++ b/src/streams/transform.js
@@ -1,5 +1,16 @@
+import {Transform} from 'stream';
+
+
 const transform = async () => {
-    // Write your code here 
+  const reverseTransform = new Transform({
+    transform(chunk, _, callback) {
+      this.push([...chunk.toString()].reverse().join(''));
+      callback();
+    },
+    encoding: 'utf-8'
+  });
+
+  process.stdin.pipe(reverseTransform).pipe(process.stdout);
 };
 
-await transform();
\ No newline at end of file
+await transform();
diff --git a/src/streams/write.js b/src/streams/write.js
index fc917160a2..6986090016 100644
--- a/src/streams/write.js
+++ b/src/streams/write.js
@@ -1,5 +1,16 @@
+import fs from 'fs';
+import path from 'path';
+import {fileURLToPath} from 'url';
+import {pipeline} from 'stream';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const write = async () => {
-    // Write your code here 
+  const filePath = path.resolve(__dirname, './files/fileToWrite.txt');
+  const fileWriteStream = fs.createWriteStream(filePath, {encoding: 'utf-8'});
+
+  process.stdin.pipe(fileWriteStream);
 };
 
-await write();
\ No newline at end of file
+await write();
diff --git a/src/wt/main.js b/src/wt/main.js
index 37d80484ec..89ca2e8b48 100644
--- a/src/wt/main.js
+++ b/src/wt/main.js
@@ -1,5 +1,40 @@
+import os from 'os';
+import {Worker} from 'worker_threads';
+import path from 'path';
+import url from 'url';
+
+const __filename = url.fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+const hostMachineCoresCount = os.cpus().length;
+
 const performCalculations = async () => {
-    // Write your code here
+  const workerPath = path.resolve(__dirname, './worker.js');
+  const workersCount = hostMachineCoresCount;
+
+  const dataForWorkers = new Array(workersCount).fill(10).map((value, index) => value + index);
+
+  const workerPromises = dataForWorkers.map(value => {
+    return new Promise((resolve, reject) => {
+      const worker = new Worker(workerPath, {
+        workerData: value
+      });
+
+      worker.on('message', value => {
+        resolve({status: 'resolved', data: value});
+        worker.terminate();
+      });
+
+      worker.on('error', () => {
+        resolve({status: 'error', data: null});
+        worker.terminate();
+      });
+    });
+  });
+
+  const results = await Promise.all(workerPromises);
+
+  console.log(results);
 };
 
-await performCalculations();
\ No newline at end of file
+await performCalculations();
diff --git a/src/wt/worker.js b/src/wt/worker.js
index 441b2154f8..732e549959 100644
--- a/src/wt/worker.js
+++ b/src/wt/worker.js
@@ -1,8 +1,11 @@
+import {parentPort, workerData} from 'worker_threads';
+
+
 // n should be received from main thread
 const nthFibonacci = (n) => n < 2 ? n : nthFibonacci(n - 1) + nthFibonacci(n - 2);
 
 const sendResult = () => {
-    // This function sends result of nthFibonacci computations to main thread
+  parentPort.postMessage(nthFibonacci(workerData));
 };
 
-sendResult();
\ No newline at end of file
+sendResult();
diff --git a/src/zip/compress.js b/src/zip/compress.js
index bb328f43c6..52823329b7 100644
--- a/src/zip/compress.js
+++ b/src/zip/compress.js
@@ -1,5 +1,25 @@
+import fs from 'fs';
+import path from 'path';
+import url from 'url';
+import zlib from 'zlib';
+import stream from 'stream';
+import utils from 'util';
+
+
+const __filename = url.fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const compress = async () => {
-    // Write your code here 
+    const sourcePath = path.resolve(__dirname, './files/fileToCompress.txt');
+    const destinationPath = path.resolve(__dirname, './files/archive.gz');
+
+    const sourceStream = fs.createReadStream(sourcePath);
+    const destinationStream = fs.createWriteStream(destinationPath);
+    const gzip = zlib.createGzip();
+
+    const pipe = utils.promisify(stream.pipeline);
+
+    await pipe(sourceStream, gzip, destinationStream);
 };
 
-await compress();
\ No newline at end of file
+await compress();
diff --git a/src/zip/decompress.js b/src/zip/decompress.js
index 69f6c345f8..644acaa4e1 100644
--- a/src/zip/decompress.js
+++ b/src/zip/decompress.js
@@ -1,5 +1,26 @@
+import fs from 'fs';
+import path from 'path';
+import url from 'url';
+import zlib from 'zlib';
+import stream from 'stream';
+import utils from 'util';
+
+
+const __filename = url.fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
 const decompress = async () => {
-    // Write your code here 
+  const sourcePath = path.resolve(__dirname, './files/archive.gz');
+  const destinationPath = path.resolve(__dirname, './files/fileToCompress.txt');
+
+  const sourceStream = fs.createReadStream(sourcePath);
+  const destinationStream = fs.createWriteStream(destinationPath);
+  const gzip = zlib.createUnzip();
+
+  const pipe = utils.promisify(stream.pipeline);
+
+  await pipe(sourceStream, gzip, destinationStream);
 };
 
-await decompress();
\ No newline at end of file
+
+await decompress();
diff --git a/src/zip/files/archive.gz b/src/zip/files/archive.gz
new file mode 100644
index 0000000000..661bf7c1a9
Binary files /dev/null and b/src/zip/files/archive.gz differ
diff --git a/src/zip/files/fileToCompress.txt b/src/zip/files/fileToCompress.txt
index 4d4efc82fe..8ba354e8ec 100644
--- a/src/zip/files/fileToCompress.txt
+++ b/src/zip/files/fileToCompress.txt
@@ -1 +1 @@
-Compress me!
\ No newline at end of file
+Compress me !