#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
#define rep(i, a, n) for (int i = a; i < n; ++i)

int main() {
    string s;
    cin >> s;

    string ans = "yukicoder";
    rep(i, 0, 9) {
        if (s[i] == '?') {
            cout << ans[i] << endl;
            return 0;
        }
    }
    return 0;
}