using System;

public class Hello
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        var a = new int[n, 5];
        for (int i = 0; i < n; i++)
        {
            string[] line = Console.ReadLine().Trim().Split(' ');
            for (int j = 0; j < 4; j++) a[i, j] = int.Parse(line[j]);
            a[i, 4] = line[4] == "YES" ? 1 : 0;
        }
        for (int i = 0; i <= 9; i++)
            if (check(a, n, i))
            {
                Console.WriteLine(i);
                break;
            }
    }
    public static bool check(int[,] a, int n, int b)
    {
        for (int i = 0; i < n; i++)
            if (a[i, 4] == 0)
            {
                for (int j = 0; j < 4; j++)
                    if (a[i, j] == b) return false;
            }
            else
            {
                var find = false;
                for (int k = 0; k < 4; k++)
                    if (a[i, k] == b) find = true;
                if (!find) return false;
            }
        return true;
    }
}