求问整除分块

#include<bits/stdc++.h>
using namespace std;
#define int unsigned long long
int n,k;
int ans;
inline void sol(){
    int l = 1,r;
    while(l <= n){
        int val = k / l;
        if(val == 0)  break;
        r = k / val;
        ans += val * ((l + r) * (r - l + 1) / 2);
        l = r + 1;
    }
}
signed main(){
    cin >> n >> k;
    sol();
    cout << k * n - ans;
}