import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String S = scan.next();
		String s = "yukicoder";
		scan.close();
		int index = 0;
		for(int i = 0; i < S.length(); i++) {
			char c = S.charAt(i);
			if(c == '?') {
				index = i;
				break;
			}
		}
		char ans = s.charAt(index);
		System.out.println(ans);
	}
}