编译失败

#include<bits/stdc++.h>
using namespace std;
int m, n, c;
int a[5010];
int b[5010];
int main() {
    cin >> k;
    bool flg = false;
    for (ll a = 1; a <= 9; a++) {
        for (ll b = 0; b <= 9; b++) {
            for (ll c = 0; c <= 9; c++) {
                if ((a * 10 + b) % k == 0 && (b * 10 + c) % k == 0 && (a * 100 + b * 10 + c) % k == 0) {
                    cout << a << b << c << endl;
                    flg = true;
                }
            }
        }
    }
    if (!flg) {
        cout << "None!" << endl;
    }
    return 0;
}