using System;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        int n = int.Parse(Console.ReadLine());
        int[] b = new int[10];
        for (int i = 0; i < 10; i++)
        {
            b[i] = 0;
        }
        string ans = "";

        for (int i = 0; i < n; i++)
        {
            string[] s = Console.ReadLine().Split(' ');

            if (s[4] == "YES")
            {
                for (int j = 0; j < 4; j++)
                {
                    if (b[int.Parse(s[j])] == 1)
                    {
                        ans = s[j];
                    }
                    else
                    {
                        b[int.Parse(s[j])] = 1;
                    }
                }
            }
            else
            {
                for (int j = 0; j < 4; j++)
                {
                    b[int.Parse(s[j])] = -1;
                }
            }
        }

        if (ans == "")
        {
            ans = Array.IndexOf(b, 0).ToString();
        }

        Console.WriteLine(ans);
    }
}