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 long n, m, k, kk, p, q, i, j, a[1001], b[1001][1001], c[1001], x,
    fix[1001];
vector<int> v[1001];
vector<int> g;
vector<int> gr[1001];
void dfs(int x) {
  int i;
  fix[x] = 1;
  v[j].push_back(x);
  for (i = 0; i < gr[x].size(); i++) {
    if (!fix[gr[x][i]]) {
      dfs(gr[x][i]);
    }
  }
}
int main() {
  cin >> q;
  cin >> x;
  for (i = 1; i <= q; i++) {
    cin >> c[i];
    if (c[i] != 0) {
      gr[i].push_back(c[i]);
      gr[c[i]].push_back(i);
    }
  }
  for (i = 1; i <= q; i++) {
    if (!fix[i]) {
      j++;
      dfs(i);
    }
  }
  m = j;
  for (i = 1; i <= m; i++) {
    for (j = 0; j < v[i].size(); j++) {
      if (v[i][j] == x) {
        kk = v[i].size() - j;
        p = i;
        break;
      }
    }
    if (kk) {
      break;
    }
  }
  for (i = 1; i <= m; i++) {
    if (i != p) {
      n++;
      a[n] = v[i].size();
    }
  }
  for (i = 1; i <= n; i++) {
    k += a[i];
  }
  for (i = 0; i <= n; i++) {
    b[i][0] = 1;
  }
  for (i = 1; i <= n; i++) {
    for (j = 1; j <= k; j++) {
      if (j >= a[i]) {
        b[i][j] = max(b[i - 1][j], b[i - 1][j - a[i]]);
      } else {
        b[i][j] = b[i - 1][j];
      }
    }
  }
  for (i = 1; i <= k; i++) {
    if (b[n][i] == 1) {
      g.push_back(i);
    }
  }
  cout << kk;
  cout << endl;
  for (i = 0; i < g.size(); i++) {
    cout << g[i] + kk << endl;
  }
}
