import java.util.Scanner;

public class Main {

	public static void main(String args[]){
		
		Scanner cin = new Scanner(System.in);
		
		String line = cin.next();
                cin.close();
		String answer = "yukicoder";
		for(int i=0;i<line.length();i++){
			if(answer.charAt(i)!=line.charAt(i)){
				System.out.println(line.charAt(i));
				break;
			}
		}
	}
}