#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
#define ALL(A) A.begin(), A.end()

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

bool ok[10];
int cnt[10];
int main()
{
	fill(ok, ok + 10, true);
	memset(cnt, 0, sizeof(cnt));

	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int N; cin >> N;
	int yescnt = 0;

	rep (i, N){
		int a[4] = {0}; rep (i, 4) cin >> a[i];
		string r; cin >> r;
		if (r == "NO"){
			rep (i, 4) ok[a[i]] = false;
		}else{ // if (r == "YES)
			++yescnt; rep (i, 4) ++cnt[a[i]];
		} // end if
	} // end rep

	rep (i, 10){
		if (ok[i] && (cnt[i] == yescnt)){
			cout << i << endl;
			break;
		} // end if
	} // end rep

	return 0;
}