#include<iostream>
#include<string>
using namespace std;

int main()
{
	int n, *a, *b, *c, *d, i, j, flag[10]{};
	string *r;
	cin >> n;
	a = new int[n];b = new int[n];c = new int[n];d = new int[n];
	r = new string[n];
	for (i = 0; i < n; i++) {
		cin >> a[i] >> b[i] >> c[i] >> d[i] >> r[i];
		if (r[i] == "NO") {
			flag[a[i]] = 1; flag[b[i]] = 1; flag[c[i]] = 1; flag[d[i]] = 1;
		}
		else {
			for (j = 0; j < 10; j++)if (j != a[i] && j != b[i] && j != c[i] && j != d[i])flag[j] = 1;;
		}
	}
	for (i = 0; i < 10; i++)if (flag[i] == 0)break;;
	cout << i << endl;
	return 0;
}