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

    class Program {
        static void Main(string[] args) {

            int n = int.Parse(Console.ReadLine());
            List<string[]> ios = new List<string[]>();
            BitArray rts = new BitArray(n);
            for (int i = 0; i < n; i++) {
                string read = Console.ReadLine();

                string rt = read.Substring(8);
                string inStr = read.Substring(0, 7);
                string[] ins = inStr.Split(' ');
                ios.Add(ins);
                rts[i] = rt == "YES";
            }

            for (int ans = 0; ans < 10; ans++) {
                bool success = true;
                for (int j = 0; j < n; j++) {
                    if (ios[j].Contains(ans.ToString()) != rts[j]) {
                        success = false;
                        break;
                    }
                }
                if (success) {
                    Console.WriteLine(ans);
                    return;
                }
            }
        }
    }