diff --git a/a1/program.c b/a1/program.c
index c817323..5c100d3 100644
--- a/a1/program.c
+++ b/a1/program.c
@@ -16,7 +16,8 @@ int main(){
     }else if(c >= 'a' && c <= 'z'){
         putchar(c - 'a' + 'A');
     }else if(c >= 'A' && c <= 'Z'){
-        putchar(c - 'A' + 'a'); 
+        putchar(c - 'A' + 'a');
+    }else if((c >= 0 && c < 32) || c == 127){   
     }else{
         putchar(c);
     }