diff --git a/du1/program.c b/du1/program.c
index 1fc9208..8c13ff2 100644
--- a/du1/program.c
+++ b/du1/program.c
@@ -7,7 +7,7 @@ int main (){
 	int counter = 0;
 	fgets(c, 100, stdin);
 	musor = getchar();
-	while(fgets(c, 100, stdin) != EOF){
+	while(fgets(c, 100, stdin) != NULL){
 		if(c[1] == '\n'){
 			if (c[0] >= 'a' && c[0] <= 'z'){
 				putchar (c[0] - 'a' + 'A');