diff --git a/adaptors_task/student/src/impl.cpp b/adaptors_task/student/src/impl.cpp
index 170c42fd..63b8dbb7 100644
--- a/adaptors_task/student/src/impl.cpp
+++ b/adaptors_task/student/src/impl.cpp
@@ -1,8 +1,37 @@
 #include "impl.h"
 #include <vector>
+#include <stack>
 
 const std::vector<std::pair<char, char>> brackets {
     {'(', ')'},
     {'[', ']'},
     {'{', '}'}
 };
+
+bool isValid(const std::string& source) {
+    std::stack<char> pairedBrackets;
+
+    for (auto const& c : source) {
+        for (auto const& bracket : brackets) {
+            if ( c == bracket.first) {
+                pairedBrackets.push(c);
+                break;
+            }
+            else if ( c == bracket.second) {
+                if (pairedBrackets.empty()) {
+                    return false;
+                }
+                char lastBracket = pairedBrackets.top();
+                pairedBrackets.pop();
+
+                for (auto const& bracket_ : brackets) {
+                    if (lastBracket == bracket_.first && c != bracket_.second) {
+                        return false;
+                    }
+                }
+                break;
+            }
+        }
+    }
+    return pairedBrackets.empty();
+}
\ No newline at end of file