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




string S;
//-----------------------------------------------------------------------------------
int main() {
	cin >> S;

	string co = "yukicoder";
	rep(i, 0, S.length()) if (S[i] == '?') {
		cout << co[i] << endl;
		return 0;
	}
}