PipeTest/Child/Child.cs

using System;

namespace PipeTest
{
    class Child
    {
        static void Main(string[] args)
        {
            var size = long.Parse(args[0]);
            for (long i = 0; i < size; ++i)
            {
                Console.Write((char)(0x20+(i & 0x3f)));
            }
        }
    }
}