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

#include <bits/stdc++.h>
using namespace std;
long n, x, nums, num[10000], qq[10000], deep[10000], q, cn[10000], sz[10000],
    usd[10000];
int main() {
  ios_base::sync_with_stdio(0);
  cin >> n >> x;
  nums = 0;
  for (int i = 1; i <= n; i++) {
    cin >> qq[i];
    q = qq[i];
    if (q == 0) {
      num[i] = nums + 1;
      nums++;
      sz[nums] = 1;
      deep[i] = 1;
    }
    if (i == x) usd[num[i]] = 1;
  }
  for (int iter = 1; iter <= 1000; iter++)
    for (int i = 1; i <= n; i++)
      if (deep[qq[i]] > 0 && deep[i] == 0) {
        q = qq[i];
        num[i] = num[q];
        sz[num[i]]++;
        deep[i] = deep[q] + 1;
        if (i == x) usd[num[i]] = 1;
      }
  cn[deep[x]] = 1;
  for (int i = 1; i <= nums; i++)
    if (usd[i] == 0)
      for (int j = 1000; j >= 0; --j)
        if (cn[j]) cn[j + sz[i]] = 1;
  for (int i = 1; i <= 1000; i++)
    if (cn[i]) cout << i << endl;
  cin.get();
  cin.get();
  return 0;
}
