diff --git a/du1/program.c b/du1/program.c
index 58a5474..91b50f0 100644
--- a/du1/program.c
+++ b/du1/program.c
@@ -1,5 +1,20 @@
 #include <stdio.h>
 int main(){
-printf("Hello, world!");
+char  word;
+	
+	for (int count = 0; (word = getchar()) != EOF;) {
+			if (word >= 'a'&&word <= 'z') {
+				word -= 32;
+			}
+			else if (word >= 'A'&&word <= 'Z'){
+				word += 32;
+			}
+			if (word == '\n') {
+				count++;
+				printf("\nPočet riadkov: %d\n", count);
+			}
+			putchar(word);
+			
+		}
 return 0;
 }