#include <bits/stdc++.h>
using namespace std;
int N, cnt1 = 0, cnt2 = 0;
int main(int argc, char *argv[]) {
  string a, b;
  cin >> N;
  for (int i = 1; i <= N; i++)
    cin >> a >> b, cnt1 += (b == "soft"), cnt2 += (b == "hard");
  for (int i = 1; i <= N; i++) {
    int q1 = i * i / 2, q2 = (i * i + 1) / 2;
    if ((q1 >= cnt1 && q2 >= cnt2) || (q2 >= cnt1 && q1 >= cnt2)) {
      printf("%d\n", i);
      return 0;
    }
  }
  return 0;
}
