#include <iostream>
#include <string>

using namespace std;

int N;
int A, B, C, D;
string R;
int possible;

int main() {
	cin >> N;
	possible = (1 << 10) - 1;
	for (int i = 0; i < N; i++) {
		cin >> A >> B >> C >> D >> R;
		if (R == "YES") {
			possible &= ((1 << A) | (1 << B) | (1 << C) | (1 << D));
		} else {
			possible &= ~((1 << A) | (1 << B) | (1 << C) | (1 << D));
		}
	}
	for (int i = 0; i < 10; i++) {
		if ((possible >> i) & 1) {
			cout << i << endl;
			break;
		}
	}
	return 0;
}