#include<bits/stdc++.h>
template<class T> inline bool chmax(T& a, T b){ if (a < b){ a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b){ if (a > b){ a = b; return true; } return false; }
using namespace std;
using ll = long long;
ll mod = 1e9+7;
const int dx[8] = {-1,0,1,0,-1,-1,1,1};
const int dy[8] = {0,1,0,-1,1,-1,1,-1};

int main(){
    string s;
    cin >> s;
    string t = "yukicoder";
    for(int i=0;i<s.size();++i){
        if (s[i]=='?') {
            cout << t[i] << endl;
            return 0;
        }
    }
}