#include <bits/stdc++.h>
using namespace std;
#define FOR(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define FORR(i,l,n) for(int (i)=l;(i)<(int)(n);++(i))
const std::string Memo = "yukicoder";
void solve() {
	std::string s;
	cin >> s;
	int index = s.find("?");	
	std::cout << Memo[index] << std::endl;

}
int main() {
	ios::sync_with_stdio(false);
	solve();
	return 0;
}