#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;


int main(){
  int N, yescnt = 0;
  cin >> N;
  map<int,int> memo1, memo2;
  rep(i,N){
    int a,b,c,d;
    string r;
    cin >> a >> b >> c >> d >> r;
    if(r=="NO"){
      memo1[a] = 1;
      memo1[b] = 1;
      memo1[c] = 1;
      memo1[d] = 1;
    }
    else{
      memo2[a]++;
      memo2[b]++;
      memo2[c]++;
      memo2[d]++;
      yescnt++;
    }
  }
  rep(i,11){
    if(memo1[i] == 0 && memo2[i] == yescnt){
      cout << i << endl;
      break;
    }
  }
  
  return 0;
}