using System;
using System.Linq;
using System.Collections.Generic;

public class P0024 {
    public static void Main() {
        var n = int.Parse(Console.ReadLine().Trim());
        var candidates = Enumerable.Range(0, 10);
        for(int i=0; i<n; i++) {
            var abcdr = Console.ReadLine().Trim().Split().ToList();
            var r = abcdr.Last();
            var cands = abcdr.Take(4).Select(int.Parse);
            if (r == "NO") {
                candidates = candidates.Except(cands);
            } else {
                candidates = candidates.Intersect(cands);
            }
        }
        Console.WriteLine(candidates.First());
    }
}