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;
int a[1024], n, x, fr[1024], dp[1024], i, j, pl;
int main() {
  cin >> n >> x;
  dp[0] = 1;
  for (i = 1; i <= n; i++) {
    cin >> a[i];
    fr[a[i]]++;
  }
  for (i = 1; i <= n; i++)
    if (!fr[i]) {
      int c = 0, flag = -1;
      for (j = i; j; j = a[j]) {
        if (j == x) flag = c;
        c++;
      }
      if (flag >= 0) {
        pl = c - flag;
        continue;
      }
      for (j = n; j >= c; j--) dp[j] |= dp[j - c];
    }
  for (i = 0; i <= n; i++)
    if (dp[i]) cout << i + pl << endl;
}
