class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            string result = "";
            for(int i = 0; i < n; i++)
            {
                string[] inputStr = Console.ReadLine().Split(' ');
                result = StringCreation(int.Parse(inputStr[0]), inputStr[1], result);
            }
            Console.WriteLine(result);
        }

        private static string StringCreation(int onoff, string str, string result)
        {
            if (onoff == 0)
            {
                 return  result + str;
            }
            else
            {
                return str + result;
            }
        }
    }