#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
	int n;
	cin >> n;

	bool ans[10];
	REP(i,10) ans[i]=true;

	int data[4];
	string ret;
	REP(i,n){
		REP(j,4) cin >> data[j];
		cin >> ret;
		if (ret == "YES"){
			 REP(j,10){
				 if(!count(data,data+4,j)) ans[j] = false;
			 }
		 }
		else {
			REP(j,n) ans[data[j]]=false;
		}
	}
	int answer;
	REP(i,10) if(ans[i]) answer = i;
	cout << answer << endl;
	return 0;
}