import java.util.Scanner;

public class MyMain {

	final static String YUKICODER = "yukicoder";

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();

		int max = 0;
		int i = 1;
		while (true) {
			final String str = generateStr(i);

			int index = s.indexOf(str);

			if (index == -1) {
				break;
			} else {
				max = i;
			}
			i++;
		}

		System.out.println(max);

		sc.close();
	}

	public static String generateStr(int n) {
		StringBuilder sb = new StringBuilder();

		for (int i = 0; i < n; i++) {
			sb.append(YUKICODER);
		}
		return sb.toString();
	}

}