#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
int isPalindrome(int num) {
    char str[10];
    sprintf(str, "%d", num);
    int len = strlen(str);
    for (int i = 0; i < len / 2; i++) {
        if (str[i] != str[len - 1 - i]) {
            return 0;
        }
    }
    return 1;
}
 
int main() {
    int N;
    printf("Enter a positive integer: ");
    scanf("%d", &N);
 
    if (isPalindrome(N)) {
        printf("%d is a black hole number.\n", N);
    } else {
        printf("%d is not a black hole number.\n", N);
    }
 
    return 0;
}