Bad input fix

du3/program.c

@@ -68,7 +68,7 @@ void process_operations(struct stack* stack) {
             char *endptr;
             float val = strtof(line, &endptr);
             if (endptr == line) { 
-                printf("no input\n");
+                printf("bad input\n");
                 return;
             }
             push_stack(stack, val);