#include<bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;

int main() {
    string ans = "yukicoder",s; cin >> s;
    rep(i,s.size()) {
        if (s[i] == '?') {
            cout << ans[i] << endl;
            break;
        }
    }
}