#include <bits/stdc++.h>

using namespace std;

int main()
{
  int N, A[4];
  int bit = (1 << 10) - 1;

  cin >> N;
  for(int i = 0; i < N; i++) {
    int build = 0;
    for(int j = 0; j < 4; j++) {
      int k;
      cin >> k;
      build |= 1 << k;
    }
    string R;
    cin >> R;
    if(R == "NO") build ^= (1 << 10) - 1;
    bit &= build;
  }
  cout << __builtin_ctz(bit) << endl;
}