#include <iostream>
#include <map>
using namespace std;
const int N = 1010, INF = 1e6;
int n, f[INF + 10], res = INF;
int main()
{
    cin >> n;
    for (int i = 0; i < n; ++i)
    {
        char op;
        int p;
        cin >> op >> p;
        p += 1;
        if (op == 'L')
            ++f[0], --f[p + 1];
        else 
            ++f[p], -- f[INF+1];
    }

    for (int i = 1; i <= INF; i++)
    {
        f[i] += f[i-1];
        res = min(res, n - f[i]);
    }

    cout << res << endl;
    return 0;
}