#include "bits/stdc++.h"

using namespace std;
using ll = long long;
const double pi = acos(-1);
#define FOR(i,a,b) for (ll i=(a),__last_##i=(b);i<__last_##i;i++)
#define RFOR(i,a,b) for (ll i=(b)-1,__last_##i=(a);i>=__last_##i;i--)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) RFOR(i,0,n)
#define __GET_MACRO3(_1, _2, _3, NAME, ...) NAME
#define rep(...) __GET_MACRO3(__VA_ARGS__, FOR, REP)(__VA_ARGS__)
#define rrep(...) __GET_MACRO3(__VA_ARGS__, RFOR, RREP)(__VA_ARGS__)
template<typename T> ostream& operator<<(ostream& os, const vector<T>& v) {
	REP(i, v.size()) { if (i)os << " "; os << v[i]; }return os;
}
template<typename T> ostream& operator<<(ostream& os, const vector<vector<T>>& v) {
	REP(i, v.size()) { if (i)os << endl; os << v[i]; }return os;
}

const ll INF = 1LL << 60;
ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;

int main() {
	ll n, a, b, c, d;
	string r;
	vector<bool> v(10, true);

	cin >> n;

	REP(i, n) {
		cin >> a >> b >> c >> d >> r;
		if (r == "NO") {
			v[a] = v[b] = v[c] = v[d] = false;
		}
		else {
			REP(j, 10) {
				if (j != a && j != b && j != c && j != d) {
					v[j] = false;
				}
			}
		}
	}

	REP(i, 10) {
		if (v[i]) {
			cout << i << endl;
			break;
		}
	}
}