diff --git a/du1/program.c b/du1/program.c
index b9e27e0..5e6a3b5 100644
--- a/du1/program.c
+++ b/du1/program.c
@@ -7,10 +7,10 @@ while((r = getchar()) !=EOF && r){
 		counter++;
 	}
 
-	if(r >= 'a' && r <= 'z'){
+	if(r >= 64 && r <= 91){
 	r = r + 32;
 	}
-	else if(r >= 'A' && r <= 'Z'){
+	else if(r >= 96 && r <= 123){
 		r = r - 32;
 	}