#include<iostream>
#include<algorithm>
#include <vector>
#include<cmath>
using namespace std;
typedef long long int lont;
int main() {
	const string A = "yukicoder";
	string B;
	cin >> B;
	int Z = B.size();
	int I;
	for (int ia = 0; ia < Z; ia++) {
		if (B.at(ia) == '?') {
			I = ia;
			break;
		}
		else continue;
	}
	cout << A.at(I) << endl;
}