import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		try (Scanner scan = new Scanner(System.in)) {
			int N = scan.nextInt();
			boolean isNo[] = new boolean[10];
			
			for(int i=0; i<N; i++) {
				int v1 = scan.nextInt();
				int v2 = scan.nextInt();
				int v3 = scan.nextInt();
				int v4 = scan.nextInt();
				String s = scan.next();
				
				if(s.equals("YES")) {
					for(int j=0; j<10; j++) {
						if(j == v1 || j == v2 || j == v3 || j == v4) continue;
						isNo[j] = true;
					}
					
				} else if(s.equals("NO")) {
					isNo[v1] = isNo[v2] = isNo[v3] = isNo[v4] = true;
				}
			}
			
			for(int i=0; i<10; i++) {
				if(isNo[i] == false) {
					System.out.println(i);
					break;
				}
			}
		}
	}
}