import java.util.Scanner;
/**
 * yukicoder no.24
 * @author scache
 *
 */
public class InferenceNumberGame {
	public static void main(String[] args) {
		InferenceNumberGame p = new InferenceNumberGame();
	}

	public InferenceNumberGame() {
		solve();
	}

	public void solve() {
		Scanner sc = new Scanner(System.in);
		int n =sc.nextInt();
		
		int res = 0x3ff;
		for(int i=0;i<n;i++){
			int cur = 0;
			for(int j=0;j<4;j++)
				cur |= 1 << sc.nextInt();
			
			if(sc.next().equals("NO"))
				res &= 0xfff ^ cur;
			else
				res &= cur;
		}
		for(int i=0;i<=9;i++){
			if((res & (1<<i))>0){
				System.out.println(i);
				return ;
			}
		}		
	}
}