diff --git a/du1/program.c b/du1/program.c
index b525181..bc3f656 100644
--- a/du1/program.c
+++ b/du1/program.c
@@ -1,6 +1,20 @@
 #include <stdio.h>
 
 int main (){
-	printf("Ahoj Svet\n");
+	int c = 0;
+	int counter = 0;
+	while(c != EOF){
+		c = getchar();
+		if (c >= 'a' && c <= 'z'){
+			putchar (c - 'a' + 'A');
+		}
+		else if ( c >= 'A' && c <= 'Z'){
+			putchar (c + 'a' - 'A');
+		}
+	counter++;
+	}
+	
+	printf("\nPočet riadkov: %d\n",counter);
+	
 	return 0;
 }