/* -*- coding: utf-8 -*-
 *
 * 24.cc: No.24 数当てゲーム - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

bool ngs[10];

/* subroutines */

/* main */

int main() {
  int n;
  cin >> n;

  for (int i = 0; i < n; i++) {
    int a, b, c, d;
    string r;
    cin >> a >> b >> c >> d >> r;

    if (r == "YES") {
      for (int j = 0; j <= 9; j++)
	if (j != a && j != b && j != c && j != d) ngs[j] = true;
    }
    else {
      ngs[a] = ngs[b] = ngs[c] = ngs[d] = true;
    }
  }

  for (int j = 0; j <= 9; j++)
    if (! ngs[j]) {
      printf("%d\n", j);
      break;
    }
  return 0;
}