[백준] 28138번 재밌는 나머지 연산 (silver 3

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

public class Main{
    public static void main(String[] args) throws IOException{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st=new StringTokenizer(br.readLine());
        long n=Long.parseLong(st.nextToken());
        long r=Long.parseLong(st.nextToken());
        long temp = (int)(Math.sqrt(n - r));

        long answer=0;
        for(long i=1; i<=temp; i++){
            if(n%i==r){
                answer+=i;
            }
            if(!((n-r)/i==i) && n%((n-r)/i)==r){
                answer+=(n-r)/i;
            }
        }
        bw.write(answer+"");
        bw.flush();

    }

}