diff --git a/du1/program b/du1/program
index c6d4661..acc2392 100755
Binary files a/du1/program and b/du1/program differ
diff --git a/du1/program.c b/du1/program.c
index e69de29..1fadac1 100644
--- a/du1/program.c
+++ b/du1/program.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+
+int main(){
+	int inp_char;
+	char out_char;
+	int count_lines = 0;
+	while(1){
+		inp_char = getchar();
+		if(inp_char >= 'A' && inp_char <= 'Z') out_char = inp_char + 32;
+		else if(inp_char >= 'a' && inp_char <= 'z') out_char = inp_char - 32;
+		else if(inp_char == EOF) break;
+		else if(inp_char == '\n') {
+			count_lines++;
+			out_char = '\n';
+		}
+		else out_char = inp_char;
+		putchar(out_char);
+	}
+	printf("\nPočet riadkov: %d\n", count_lines);
+	return 0;
+}