import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String S = sc.next();
        String T = "yukicoder";
        for(int i=0; i<S.length(); i++){
            if(S.charAt(i)=='?'){
                System.out.println(T.charAt(i));
                System.exit(0);
            }
        }
    }
}