#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<map>
#include<set>
#include<cstdio>
#include<cmath>
#include<numeric>
#include<queue>
#include<stack>
#include<cstring>
#include<limits>
#include<functional>
#include<unordered_set>
#include<iomanip>
#include<cassert>
#include<regex>
#define rep(i,a) for(int i=(int)0;i<(int)a;++i)
#define pb push_back
#define eb emplace_back
using ll=long long;
constexpr ll mod = 1e9 + 7;
constexpr ll INF = 1LL << 50;
 
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
using namespace std;

void solve(){
    int n;
    cin>>n;
    set<int>s;
    rep(i,10)s.insert(i);
    vector<vector<int>>a(n,vector<int>(4));
    string r;
    rep(i,n){
        rep(j,4)cin>>a[i][j];
        cin>>r;
        if(r=="NO")rep(j,4)s.erase(a[i][j]);
        else {
            rep(j,10){
                if(j==a[i][0]||j==a[i][1]||j==a[i][2]||j==a[i][3])continue;
                else s.erase(j);
            }
        }
    }
    cout<<*s.begin()<<"\n";
}
 
int main(){
	ios::sync_with_stdio(false);
    cin.tie(0);
	cout<<fixed<<setprecision(15);
	solve();
	return 0;
}