#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <vector>
#include <string>
#include <set>
#include <map>

using namespace std;

int main() {
	string s = "yukicoder";
	string t;
	cin >> t;
	int pos = t.find('?');
	cout << s[pos] << endl;
}