using System;

static class SqrtPrecalculated

{

    public const int MaxValue = 100;

    // Static field

    private static int[] sqrtValues;

    // Static constructor

    static SqrtPrecalculated()

    {

        sqrtValues = new int[MaxValue + 1];

        for (int i = 1; i < sqrtValues.Length; i++)

        {

            sqrtValues[i] = (int)Math.Sqrt(i);

        }

    }

    // Static method

    public static int GetSqrt(int value)

    {

        if ((value < 0) || (value > MaxValue))

        {

            throw new ArgumentOutOfRangeException(String.Format(

                "The argument should be in range [0...{0}].",

                MaxValue));

        }

        return sqrtValues[value];

    }

}

public class SqrtTest

{

    public static void Main()

    {

        Console.WriteLine(SqrtPrecalculated.GetSqrt(254));

        // Result: 15

    }

}