diff --git a/cv1/program.c b/cv1/program.c
index 466e1f0..41d48b1 100644
--- a/cv1/program.c
+++ b/cv1/program.c
@@ -1,26 +1,32 @@
 #include <stdio.h>
-#include <ctype.h>
 
 int main() {
-    int lines_count = 0;
     int c;
+    int lines_count = 0;
 
     while ((c = getchar()) != EOF) {
-        if (islower(c)) {
-            putchar(toupper(c));
-        } else if (isupper(c)) {
-            putchar(tolower(c));
-        } else {
-            putchar(c);
-            if (c == '\n') {
-                lines_count++;
-            }
+        // Check if the character is a lowercase letter
+        if (c >= 'a' && c <= 'z') {
+            // Convert lowercase to uppercase
+            c = c - 'a' + 'A';
         }
+        // Check if the character is an uppercase letter
+        else if (c >= 'A' && c <= 'Z') {
+            // Convert uppercase to lowercase
+            c = c - 'A' + 'a';
+        }
+        // Check if the character is an end of line
+        else if (c == '\n') {
+            // Increment line count
+            lines_count++;
+        }
+
+        // Output the character
+        putchar(c);
     }
 
-    printf("Počet načítaných riadkov: %d\n", lines_count);
+    // Print the number of lines read
+    printf("Lines count: %d\n", lines_count);
 
     return 0;
-    
-
-}
\ No newline at end of file
+}