diff --git a/misc/lexicographic_permutations.c b/misc/lexicographic_permutations.c
index cccb9fbb..10f8cedf 100644
--- a/misc/lexicographic_permutations.c
+++ b/misc/lexicographic_permutations.c
@@ -50,9 +50,13 @@ void PrintSortedPermutations(char *str)
 
 int main()
 {
-    unsigned int n;  // size of string
-    scanf("%u\n", &n);
-
+    int n;  // size of string
+    scanf("%d\n", &n);
+    if (n <= 0 || n >= 1000)
+    {
+        perror("Input number out of range: >0 and <1000\n");
+        return -1;
+    }
     char *str = (char *)malloc(n * sizeof(char));
     scanf("%s", str);
     PrintSortedPermutations(str);