#include <iostream>
#include <iomanip>
#include <cmath>

typedef long long ll;

int main(void)
{
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(13);
  std::string s;
  std::cin >> s;
  std::string yukicoder = "yukicoder";
  for (int i = 0; i < s.size(); ++i) {
    if (s[i] == '?') {
      std::cout << yukicoder[i] << std::endl;
      return 0;
    }
  }
  return 0;
}