using System;

public class Program

{

    public static float Floor(float f)

    {

        return (float) Math.Floor((double) f);

    }

    public static float PingPong(float t, float length)

    {

      t = Repeat(t, length * 2f);

      return length - Math.Abs(t - length);

    }

    public static float Repeat(float t, float length)

    {

      return t - Floor(t / length) * length;

    }

    public static void Main()

    {

        for(float i = 0.0f; i < 10.0f; i += 0.1f)

        {

            Console.WriteLine($"{PingPong(i, 1)}");

        }

    }

}