#include <bits/stdc++.h>

using namespace std;

#define REP(i, n) for(int i = 0; i < n; i++)

int main() {
    string s, t = "yukicoder";
    cin >> s;

    REP(i, s.length()) {
        if (s[i] == '?') {
            cout << t[i] << endl;
            return 0;
        }
    }
}