#include <bits/stdc++.h>

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

vector<int> g[100100];
bool done[100100] = {false};
vector<int> sol;

bool dfs(int node){
  done[node] = true;
  if(g[node].size() == 0){
    sol.push_back(node);
    return true;
  }
  bool ok = true;
  for(auto i : g[node]){
    ok &= !dfs(i);
  }
  if(ok) sol.push_back(node);
  return ok;
}

int main()
{
  int n;
  cin >> n;
  for(int i = 1; i <= n; ++i){
    char c;
    cin >> c;
    if(c == 'V'){
      int j;
      cin >> j;
      g[j].push_back(i);
    }
  }
  for(int i = 1; i <= n; ++i){
    if(!done[i]){
      dfs(i);
    }
  }
  cout << sol.size() << endl;
  for(auto i : sol)
    cout << i << " ";
  return 0;
}