diff --git a/cv1/program.c b/cv1/program.c
index 4839991..89c0ecd 100644
--- a/cv1/program.c
+++ b/cv1/program.c
@@ -1,38 +1,25 @@
 #include <stdio.h>
-
-char simulate_caps_lock(char c) {
-    if ('a' <= c && c <= 'z') {
-        return c - ('a' - 'A');
-    } else if ('A' <= c && c <= 'Z') {
-        return c + ('a' - 'A');
-    } else {
-        return c;
-    }
-}
+#include <ctype.h>
 
 int main() {
-    char c;
     int line_count = 0;
+    char input_char;
 
-    while (1) {
-        int input = getchar();
-
-        if (input == EOF) {
-            return -1;
-        }
-
-        c = (char)input;
-        c = simulate_caps_lock(c);
-
-        putchar(c);
-
-        if (c == '\n') {
+    while ((input_char = getchar()) != EOF) {
+        if (input_char == '\n') {
             line_count++;
         }
+
+        if (islower(input_char)) {
+            input_char = toupper(input_char);
+        } else if (isupper(input_char)) {
+            input_char = tolower(input_char);
+        }
+
+        putchar(input_char);
     }
 
-    printf("%d\n", "Lines count: "line_count);
+    printf("\nLines␣count:%d\n", line_count);
 
     return 0;
 }
-