#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
using namespace std;

int main() {
    int n; cin >> n;
    vector<bool> is(11, true);
    vector<int> cnt(11, 0);
    rep(i, n) {
        int a, b, c, d; cin >> a >> b >> c >> d;
        string r; cin >> r;
        if(r == "NO") {
            is[a] = is[b] = is[c] = is[d] = false;
        } else {
            for(int i = 1; i < 10; ++i) {
                if(i != a && i != b && i != c && i != d) is[i] = false;
            }
        }
    }
    rep(i, 9) {
        if(is[i+1]) {
            cout << i + 1 << endl;
            return 0;
        }
    }
    return 0;
}