import java.util.*;

class Main {
	static Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {
		
		String y = "yukicoder";
		String s = sc.next();
		
		for (int i=0; i<9; i++) {
			if (s.charAt(i) == '?') {
				System.out.println(y.charAt(i));
				return;
			}
		}
		
	}
}