#include <cstdio>
#include <iostream>
#define REP(i,n) for(int i=0;i<n;i++)
int main(){
	int n, a[4];
	std::string r;
	bool no[10] = {false};

	scanf("%d", &n);
	while(n--){
		scanf("%d %d %d %d", &a[0], &a[1], &a[2], &a[3]);
		std::cin >> r;
		if(r == "NO")	REP(i,4)	no[a[i]] = true;
		else	REP(i,10)	if(i!=a[0] && i!=a[1] && i!=a[2] && i!=a[3])	no[i] = true;
	}

	REP(i,10){
		if(no[i]==false){
			printf("%d\n", i);
			break;
		}
	}
}