import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Tester {

	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String base = "yukicoder";
		String str = br.readLine();
		int num = str.indexOf('?');
		System.out.println(base.charAt(num));
	}

}