import java.util.*;
import java.util.stream.Stream;

public class No494 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
		String yukicoder = "yukicoder";
		String s = sc.next();
		for(int i = 0 ; i < s.length(); i++) {
			if(s.charAt(i) == '?') {
				System.out.println(yukicoder.charAt(i));
				return;
			}
		}
	}
}