#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int a;
  cin >> a;
  if ((a >= 2800) && (a <= 5000)) {
    string s;
    cin >> s;
    cout << s << "\n";
  } else {
    cout << "error"
         << "\n";
  }
}
