#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <cstring>
#include <map>
#include <utility>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <sstream>
#include <complex>
#include <stack>
#include <queue>
#include <unordered_set>
#include <unordered_map>
using namespace std;

auto str = "yukicoder";

int main(void)
{
	for (int i = 0; i < 114514; ++i)
	{
		char c;
		cin >> c;
		if (c == '?')
		{
			cout << str[i] << endl;
			break;
		}
	}
	return 0;
}