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

int main(){
	int n;
	int a[6], b[6], c[6], d[6]; string r[6];
	
	cin >> n;
	for( int i = 0; i < n; i++ ){
		cin >> a[i] >> b[i] >> c[i] >> d[i] >> r[i];
	}
	for( int val = 0; val < 10; val++ ){
		int i;
		for( i = 0; i < n; i++ ){
			int res = ( r[i] == "YES" ) ^ ( val == a[i] || val == b[i] || val == c[i] || val == d[i] );
			if( res )
				break;
		}
		if( i == n ){
			cout << val << endl;
			return 0;
		}
	}
	return 0;
}