Poj Solution 2800

http://poj.org/problem?id=2800

//* @author: <strong>Yeming&nbsp;Hu</strong>&quot;cslittleye@gmail.com&quot;
import java.util.Scanner;

public class Main
{
    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
    long n,k;
    while(sc.hasNext())
    {
        n = sc.nextLong();
        k = sc.nextLong();
        long sum;
        if(n<=k)
        {
            sum = sumMod(k,n);
        }else
        {
            sum = sumMod(k,k);
        sum += (n-k)*k;
        }

        System.out.println(sum);
    }
    }

    static long sumMod(long k, long n)
    {
        long sum = 0;
    long d = k/n;
    long t1 = n;
    long t2 = k/(d+1);
    while(k/d - t2 > 10)
    {
        long s = k%t1;
        long e = k%(t2+1);
        sum += (s+e)*(t1-t2)/2;
        d++;
        t1 = t2;
        t2 = k/(d+1);
    }

    for(long i=2;i<=t1;i++)
    {
        sum += k%i;
    }

    return sum;
    }
}