#include <iostream>
#include <vector>

using namespace std;

struct adat { int erv, cel; };
vector <adat> x;
int N;

void cs(int k, int h)
{
    if (x[k].cel == 0) return;
    x[x[k].cel].erv += h;
    cs(x[k].cel, -h);
}

int main()
{
    cin >> N;
    x.resize(N + 1);
    char tip;
    int c;

    for (int i = 1; i <= N; ++i)
    {
        cin >> tip;
        if (tip == 'R') x[i].erv = 0;
        else
        {
            cin >> c;
            x[i].cel = c;
            cs(i, 1);
        }
    }

    vector <int> r;
    for (int i = 1; i <= N; ++i)
        if (x[i].erv == 0) r.push_back(i);

    cout << r.size() << '\n';
    for (auto e : r)
        cout << e << ' ';

    return 0;
}
/*
7
R
V 1
R
V 2
V 3
V 3
V 5
*/