diff --git a/cv1/program.c b/cv1/program.c
index 29cab5e..9fb5506 100644
--- a/cv1/program.c
+++ b/cv1/program.c
@@ -1,7 +1,23 @@
-#include<stdio.h>
+#include <stdio.h>
 
-int main(){
+int main() {
+    int text;
 
-	printf("hello world\n");
+    while ((text = getchar()) != EOF) {
+        if (text >= 'a' && text <= 'z') {
+            text = text - 'a' + 'A';
+        } else if (text >= 'A' && text <= 'Z') {
+            text = text - 'A' + 'a';
+        } else if (text == '\n') {
+            printf("\n");
+            continue;
+        } else if (text < 32 || text == 127) {
+            continue;
+        }
 
+        putchar(text);
+    }
+
+    printf("\nPocet riadkov: 1\n"); 
+    return 0;
 }