//c++

#include <iostream>

using namespace std;

signed main() {

int x, N, _min = 30001;

cin >> N;

for (int i = 0; i < N; i++) {

 cin >> x;

 if (x < _min && x % 10 == 4)

  _min = x;

}

cout << _min << endl;

return 0;

}