import java.util.Scanner;

public class Main{
    static final Scanner sc = new Scanner(System.in);
    public static void main(String[] args){
        String str = sc.next();
        
        System.out.println(search(str));
    }
    
    static char search(String str){
        String moto = "yukicoder";
        for(int i=0; i<str.length(); i++){
            if(str.charAt(i) == '?'){
                return moto.charAt(i);
            }
        }
        return 0;
    }
}