#include <bits/stdc++.h>
#define rep(i, a, n) for (int i = a; i < n; i++)
#define repr(i, a, n) for (int i = n - 1; i >= a; i--)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  int n;
  cin >> n;
  vector<int> ans(10);
  rep(i, 0, 10) ans[i] = i;
  rep(i, 0, n) {
    int v[4];
    string s;
    cin >> v[0] >> v[1] >> v[2] >> v[3] >> s;
    if (s == "YES") {
      sort(v, v + 4);
      int ind = 0;
      rep(i, 0, 10) {
        if (i != v[ind]) {
          ans[i] = -1;
        } else {
          ind++;
        }
      }
    } else {
      for (auto m : v) {
        ans[m] = -1;
      }
    }
  }

  rep(i, 0, 10) {
    if (ans[i] != -1) {
      cout << ans[i] << endl;
      return 0;
    }
  }
}