题目地址
#include<cstdio>
#include<iostream>
#define ll long long
using namespace std;
int main(){
ll n,k;
scanf("%lld %lld",&n,&k);
ll ans=n*k;
int gx;
for(int x=1;x<=n;x=gx+1){
gx=k/x?min(k/(k/x),n):n;
ans-=(k/x)*(x+gx)*(gx-x+1)/2;
}
printf("%lld\n",ans);
return 0;
}
