20 20
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 10 4
0 1 4 2 7 0 10 0 5 8
 10 7
10 8 6 5 0 0 0 4 3 9
 10 1
8 7 0 2 0 10 0 0 3 5
 10 7
7 9 2 10 0 0 0 3 5 1
 10 2
10 0 9 0 0 4 2 6 8 0
 10 2
0 7 0 10 8 0 4 2 3 0

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
 3
4
8
9
 1
5
6
10
 2
4
5
7
8
10
 1
2
6
7
 1
2
3
4
6
7
8
9
 4
5
6
7
8

import java.util.*;

public class B {
	private static Scanner in;

	public void run() {
		int n = in.nextInt();
		int m = in.nextInt() - 1;
		int[] a = new int[n];
		int[] b = new int[n];
		Arrays.fill(b, -1);
		boolean[] mark = new boolean[n];
		for (int i = 0; i < n; i++) {
			a[i] = in.nextInt() - 1;
			if (a[i] >= 0) {
				b[a[i]] = i;
			}
		}
		int p = -1;
		ArrayList<Integer> chains = new ArrayList<Integer>();
		for (int i = 0; i < n; i++) {
			if (mark[i]) {
				continue;
			}
			int j = i;
			while (a[j] >= 0) {
				j = a[j];
			}
			int size = 0;
			int pos = -1;
			while (j >= 0) {
				mark[j] = true;
				if (j == m) {
					pos = size;
				}
				size++;
				j = b[j];
			}
			if (pos >= 0) {
				p = pos;
			} else {
				chains.add(size);
			}
		}
		boolean[] c = new boolean[n + 1];
		c[0] = true;
		for (int x : chains) {
			for (int i = n; i >= 0; i--) {
				if (c[i]) {
					c[i + x] = true;
				}
			}
		}
		for (int i = 0; i <= n; i++) {
			if (c[i]) {
				System.out.println(i + p + 1);
			}
		}
	}

	public static void main(String[] args) {
		Locale.setDefault(Locale.US);
		in = new Scanner(System.in);
		new B().run();
		in.close();
	}
}
