diff --git a/dz12.1 b/dz12.1
new file mode 100644
index 0000000..cc740bf
--- /dev/null
+++ b/dz12.1
@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+int Reg(char *s1, char *s2) //всі великі букви переводить в малі
+{
+  FILE *f1; FILE *f2;
+  f1 = fopen(s1, "r");
+  f2 = fopen(s2, "w");
+  while(!feof(f1))
+  {
+      char c;
+      fscanf(f1,"%c",&c);
+      if(isupper(c))
+      {
+        c = tolower(c);
+      }
+      fprintf(f2, "%c", c);
+  }
+  fclose(f1);
+  fclose(f2);
+  return 1;
+}
+int Rev(char *s1, char *s2) // записати рядок у зворотньому порядку
+{
+  FILE *f1; FILE *f2;
+  f1 = fopen(s1, "r");
+  f2 = fopen(s2, "w");
+  char *r;
+  r = (char *) malloc(sizeof(char));
+  int n = 0;
+  while(!feof(f1))
+  {
+    char c;
+    fscanf(f1,"%c", &c);
+    r[n] = c;
+    n++;
+    r = (char *) realloc(r, sizeof(char));
+  }
+  for(int i = 0; i < n/2; i++)
+  {
+    char s = r[n - i - 1];
+    r[n - i - 1] = r[i];
+    r[i] = s;
+
+  }
+  for(int i = 0; i < n; i++)
+  {
+    fwrite(&r[i], sizeof(char),1 ,f2);
+  }
+  free(r);
+  fclose(f1);
+  fclose(f2);
+
+  return 1;
+}
+
+
+int main()
+{
+  char *s1, *s2;
+  s1 = "file1.txt";
+  s2 = "file2.txt";
+
+  Rev(s1,s2);
+
+}