#include <iostream>
#include <string>

int main() {
	std::string str, yuki = "yukicoder";
	std::cin >> str;

	for (int i = 0; i < 9; i++) {
		if (str[i] == '?') {
			std::cout << yuki[i] << std::endl;
			break;
		}
	}

	return 0;
}