Java Code to implement Fermat's algorithm

Problem:

An algorithm due to Fermat can be used to find the largest factor f (less than or equal to squareroot(n)) of an odd integer.

Solution:

package com.myprograms;

import java.util.Scanner;

public class FermatAlgorithm {

public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
        System.out.println("Enter odd number");
        long N = scan.nextLong();
        FermatAlgorithm fermatAlgorithm = new FermatAlgorithm();
        fermatAlgorithm.findFermatFactor(N);
        scan.close();

}

public boolean isSquare(long N)
    {
        long sqr = (long) Math.sqrt(N);
        if (sqr * sqr == N || (sqr + 1) * (sqr + 1) == N)
            return true;
        return false;
    }

public void display(long r1, long r2)
    {
        System.out.println("\nRoots = "+ r1 +" , "+ r2);  
    }

public void findFermatFactor(long N)
   {
       long a = (long) Math.ceil(Math.sqrt(N));
       long b2 = a * a - N;
       while (!isSquare(b2))
       {
           a++;
           b2 = a * a - N;
       }
       long r1 = a - (long)Math.sqrt(b2);
       long r2 = N / r1;
       display(r1, r2);
   }

}

Output:

Enter odd number
5959

Roots = 59 , 101