#include <algorithm>
#include <iostream>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <cmath>
#include <stack>
using namespace std;

int main() {
	int N;
	cin >> N;
	bool isTarget[10]={0};

	int N1,N2,N3,N4;
	string str;
	cin >> N1 >> N2>> N3>> N4>> str;
	if (str == "NO"){
		for (int i = 0;i<10;i++){
			if(i != N1 && i != N2 &&i != N3&&i != N4){
				isTarget[i] = true;
			}else{
				isTarget[i] = false;
			}
		}
	}else{
		for (int i = 0;i<10;i++){
			if(i == N1 || i == N2 || i == N3 || i == N4){
				isTarget[i] = true;
			}else{
				isTarget[i] = false;
			}
		}
	}

	for (int i = 0;i<N-1;i++){
		int Na[4];
		string str;
		cin >> Na[0] >> Na[1]>> Na[2]>> Na[3]>> str;
		if (str == "NO"){
			for(int j=0;j<4;j++){
				isTarget[Na[j]] = false;
			}
		}else{
			for (int i = 0;i<10;i++){
				if (isTarget[i]){
					if(i == Na[0]|| i == Na[1]|| i == Na[2] || i ==Na[3]){
						isTarget[i] = true;
					}else{
						isTarget[i] = false;
					}
				}
			}
		}
	}

	for (int i = 0;i<10;i++){
		if (isTarget[i]){
			cout << i << endl;
			return 0;
		}
	}
}