Problem:
Score : 400 points

Problem Statement

Takahashi had a pair of two positive integers not exceeding N, (a,b), which he has forgotten.
He remembers that the remainder of a divided by b was greater than or equal to K.
Find the number of possible pairs that he may have had.

Constraints

1 \leq N \leq 10^5

0 \leq K \leq N-1

All input values are integers.

Input

Input is given from Standard Input in the following format:

N K

Output

Print the number of possible pairs that he may have had.

Sample Input 1

5 2

Sample Output 1

7

There are seven possible pairs: (2,3),(5,3),(2,4),(3,4),(2,5),(3,5) and (4,5).

Sample Input 2

10 0

Sample Output 2

100

Sample Input 3

31415 9265

Sample Output 3

287927211

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;
import java.io.*;

public class Main {

	public static void main(String[] args)
	{
			Scanner in = new Scanner(System.in);
			int N = in.nextInt(), K = in.nextInt(), cnt = 0;

			for(int a = K; a <= N; a++)
			{
				for(int b = K; b <= N; b++)
				{
					if(b == 0)
						continue;
					int val = a % b;
					if(val >= K) {
						cnt++;
					}
				}
			}
			System.out.println(cnt);
	}
    
}