#include <iostream>
using namespace std;

int a[10];

int main() {
  int n, A, B, C, D;
  string s;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> A >> B >> C >> D;
    cin >> s;
    if (s == "YES") {
      for (int j = 0; j < 10; j++) {
        if (j != A && j != B && j != C && j != D) {
          a[j] = 1;
        }
      }
    } else {
      a[A] = a[B] = a[C] = a[D] = 1;
    }
  }
  for (int i = 0; i < 10; i++) {
    if (a[i] == 0) {
      cout << i << endl;
      break;
    }
  }
  return 0;
}