using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(solution(4,17));

    }

    public static int solution(int A, int B)

    {

        int count = 0;

        for (int i = A; i <= B; i++)

        {

            if(SquareRootCheck(i))

            {

                count+=1;

            }

        }

        return count;

    }

    public static bool SquareRootCheck(int num)

    {

        int sqrt = (int)Math.Sqrt(num);

        return (int)Math.Pow(sqrt,2) == num;

    }

}