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: Time Limit Exceeded)

import java.util.Scanner;
import java.util.Arrays;

public class Main {

public static void main(String [] args){

        int N,K;
        int count =0;
        Scanner input = new Scanner(System.in);

        N = input.nextInt();
        K = input.nextInt();

        for (int i=1; i<=N; i++ ) {
                for (int j=1; j<=N; j++ ) {
                        if (i%j >=K) {
                                count++;
                        }
                }
        }

        System.out.println(count);
}
}