diff --git a/04/solution.c b/04/solution.c
index 68e96a5..88dab3d 100644
--- a/04/solution.c
+++ b/04/solution.c
@@ -3,7 +3,7 @@
 int main(void) {
     int a, b, c, d, S = 0, G = 0;
 
-    while (scanf("%d-%d,%d-%d", &a, &b, &c, &d) == 4) {
+    while (scanf("%u-%u,%u-%u", &a, &b, &c, &d) == 4) {
         S += (a >= c && b <= d) || (c >= a && d <= b);
         G += (a <= c && b >= c) || (c <= a && d >= a);
     }