#include<iostream>
#include<algorithm>
#include<string>

using namespace std;


int main(){
	int N;
	int A[N],B[N],C[N],D[N];
	string R;
	cin >> N;
	bool ans[10];
	for(int i=0;i<10;i++)
		ans[i] = true;


	for(int i = 0; i < N; i++){
		cin >> A[i] >> B[i] >> C[i] >> D[i] >> R;
		if(R == "NO"){
			ans[A[i]] = false;
			ans[B[i]] = false;
			ans[C[i]] = false;
			ans[D[i]] = false;
		}
		else{
			for(int j = 0; j < 10;j++){
				if(j != A[i] && j != B[i] && j != C[i] && j != D[i])
					ans[j] = false;
			}
		}
	}
	for(int i=0;i < 10;i++){
		if(ans[i]){
			cout << i << endl;
			break;
		}
	}

	return 0;
}