#include <iostream>
#include <string>
#include <algorithm>
#include <queue>
#include <vector>
#include <cmath>
#include <cctype>
#define rep(i,a,b) for(int i=(a);i<b;i++)
#define INF 1000000000
#define MAX_N 100000000
using namespace std;
bool debug=false;

int main(){
  string s="yukicoder",ss;
  cin>>ss;
  for(int i=0;i<s.size();i++){
    if(ss[i]=='?'){
      cout<<s[i]<<endl;
      break;
    }
  }
  return 0;
}