using System;

using System.Numerics;

public class Program

{

    public static void Main()

    {

        for(int i = 0; i < 25; i++){

            Vector2 vec = getPoint(i);

            int num = getNum(vec);

            Console.WriteLine($"{i}  -  {vec}  -  {num}");

        }

    }

    private static Vector2 getPoint(int num)

    {

        int frq = (int)MathF.Sqrt(num+1);

        if (frq >= MathF.Sqrt(num)) return new Vector2(frq-1, frq-1);

​

        int dis = num - (int)MathF.Pow(frq, 2);

        if (dis < frq) return new Vector2(dis, frq);

​

        return new Vector2(frq, dis - frq);

    }

    private static int getNum(Vector2 pos)

    {

        if (pos.X == pos.Y) return (int)MathF.Pow(pos.X + 1, 2);

        if (pos.X < pos.Y) return (int)pos.X + (int)MathF.Pow(pos.Y, 2);

        return (int)(pos.X + Math.Pow(pos.X, 2) + pos.X);

    }

​

}