public static int largestPrime(long n)
{
    int limit=(int)Math.sqrt(n)+1;
    boolean [] numbers = new boolean[limit];
    Arrays.fill(numbers,true);
    int largestPrimeFactor=1;
    for(int count=2;count<limit;count++)
    {
        if(numbers[count]==true)
        {
            for(int i=2;i*count<limit;i++)
                numbers[count*i]=false;
            if(n%count==0)
                largestPrimeFactor=count;
        }

    }
    return largestPrimeFactor;
}