#include "bits/stdc++.h"
using namespace std;

typedef long long Int;
#define REP(i,n) for(int (i)=0;(i)<(int)(n);++(i))

int main() {
	int N; cin >> N;
	int a[6][4];
	string s[6];
	REP(i, N) {
		REP(j, 4) cin >> a[i][j];
		cin >> s[i];
	}

	for (int ans = 0; ans <= 9; ans++) {
		bool ok = true;
		REP(t, N) {
			bool isin = a[t][0] == ans || a[t][1] == ans || a[t][2] == ans || a[t][3] == ans;
			ok = ok && isin == (s[t] == "YES");
		}
		if (ok) {
			cout << ans << endl;
			break;
		}


	}

}