#include <stdio.h>
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <functional>
#include <map>
#include <iomanip>
#include <math.h> 
#include <stack>
#include <queue>
#include <bitset>
#include <cstdlib>
#include <tuple>
#include <cctype>
#include <ctype.h>
#include <set>
#include <sstream>

using namespace std;


int main(){
	int i, j, k;
	int n;
	vector<vector<int>>y(0, vector<int>(4));
	vector<vector<int>>no(0, vector<int>(4));
	vector<bool>flag(10, false);
	vector<int>flag2(11, 0);


	cin >> n;


	for (i = 0; i < n; i++) {
		int n1, n2, n3, n4;
		string s;
		cin >> n1 >> n2 >> n3 >> n4 >> s;
		if (s == "YES") {
			y.push_back({ n1,n2,n3,n4 });
		}
		else if (s == "NO") {
			no.push_back({ n1,n2,n3,n4 });
		}

	}

	for (i = 0; i < no.size(); i++) {
		flag[no[i][0]] = true;
		flag[no[i][1]] = true;
		flag[no[i][2]] = true;
		flag[no[i][3]] = true;
	}

	int cnt = 0;
	int index = 0;

	for (i = 0; i < 10; i++) {
		if (flag[i] == false) {
			cnt++;
			index = i;
		}
	}

	if (cnt == 1) {
		cout << index << endl;
		getchar();
		getchar();
		return 0;
	}


	for (i = 0; i < y.size(); i++) {
		if (flag[y[i][0]] == false)flag2[y[i][0]]++;
		if (flag[y[i][1]] == false)flag2[y[i][1]]++;
		if (flag[y[i][2]] == false)flag2[y[i][2]]++;
		if (flag[y[i][3]] == false)flag2[y[i][3]]++;
	}

	for (i = 0; i < 11; i++) {
		if (flag2[i] >= 2) {
			cout << i << endl;
			break;
		}
	}





	getchar();
	getchar();
	return 0;
}