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.Arrays;
import java.util.LinkedList;
import java.util.Scanner;

public class B {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int x = in.nextInt() - 1;
        int[] F = new int[n];
        int[] B = new int[n];
        Arrays.fill(B, -1);
        for (int i = 0; i < n; i++) {
            int y = in.nextInt() - 1;
            F[i] = y;
            if (y != -1)
                B[y] = i;
        }
        LinkedList<Integer> E = new LinkedList<Integer>();
        for (int i = 0; i < n; i++)
            if (F[i] == -1) {
                int temp = i;
                boolean found = false;
                int cnt = 0;
                while (temp != -1) {
                    cnt++;
                    found |= temp == x;
                    temp = B[temp];
                }
                if (!found)
                    E.add(cnt);
            }
        int front = 0;
        while (x != -1) {
            x = F[x];
            front++;
        }
        boolean[] can = new boolean[n + 1];
        can[0] = true;
        for (int y : E)
            for (int i = n; i >= 0; i--)
                if (i + y <= n)
                    can[i + y] |= can[i];
        for (int i = 0; i <= n; i++)
            if (can[i])
                System.out.println(front + i);
    }
}
