#include <bits/stdc++.h>

using namespace std;
using ll = long long int;
const ll inf = 1e9;

int main()
{
  int n;
  cin >> n;
  vector<int> v(n + 1);
  vector<bool> head(n + 1, true);
  for(int i = 1; i <= n; ++i){
    char c;
    cin >> c;
    if(c == 'V'){
      int j;
      cin >> j;
      head[j] = false;
      v[i] = j;
    }
  }
  vector<bool> active(n + 1, true);
  for(int i = 1; i <= n; ++i){
    if(head[i]){
      int ptr = v[i], ctr = 0;
      while(ptr != 0){
        active[ptr] = ctr % 2;
        ++ctr;
        ptr = v[ptr];
      }
    }
  }
  vector<int> sol;
  for(int i = 1; i <= n; ++i){
    if(active[i]) sol.push_back(i);
  }
  cout << sol.size() << endl;
  for(auto i : sol)
    cout << i << " ";
  return 0;
}