我本地测试了一些数据，都通过了，我觉得应该没问题
大牛帮看看是怎么回事
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;


public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
		String line = stdin.readLine();
		StringTokenizer st = new StringTokenizer(line);
		int n = Integer.parseInt(st.nextToken());
		int k = Integer.parseInt(st.nextToken());
		
		long result = 0;
		if(n > k) {
			result = (n-k)*k;
			n = k-1;
		}
		
		for(int i=2;i<n+1;i++) {
			int shang = k/i;
			int in = k/shang;
			if(in>n)
				in = n;
			int yu = k%i;
			int num;
			if((num = in-i+1) > 1){
				result += yu*num +num*(num-1)*(-shang)/2;
				i = in;
			}else
				result += yu;
		}
		
		System.out.println(result);

	}

}