#include <bits/stdc++.h>
using namespace std;

int reverse_number(int x) {
    int rev = 0;
    while (x > 0) {
        rev = rev * 10 + x % 10;
        x /= 10;
    }
    return rev;
}

int main() {
    for (int N = 1000; N <= 9999; ++N) {
        int rev_N = reverse_number(N);
        if (9 * N == rev_N) {
            cout << N << endl;
        }
    }
    return 0;
}