TSORT in SPOJ

using System;
using System.Collections.Generic;
using System.Text;

namespace TSORT
{

    class ContestUtil
    {
        public static int ParseInt(string str)
        {
            str.Trim();
            int ret = 0;

            for (int i = 0; i < str.Length; i++)
            {
                ret += (str[i] - '0') * (int)Math.Pow(10, str.Length - i - 1);
            }
            return ret;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            int numbers_count = int.Parse(Console.ReadLine());
            int[] numbers = new int[1000000];

            int tmp;
            for (int i = 0; i < numbers_count; i++)
            {
                tmp = ContestUtil.ParseInt(Console.In.ReadLine());
                numbers[tmp] += 1;
            }


            StringBuilder sb = new StringBuilder();

            for (int i = 0; i < 1000000; i++)
            {
                for (int j = 0; j < numbers[i]; j++)
                {
                    sb.AppendLine(i.ToString());
                }
            }

            Console.Write(sb.ToString());
        }
    }
}