#include<bits/stdc++.h>
#define rep(i,s,n) for (int i = (int)(s); i < (int)(n); i++)
#define all(v) begin(v),end(v)
using namespace std;
using ll = long long;
bool chmin(auto &a, auto b){ return a > b ? a = b, 1 : 0; }
bool chmax(auto &a, auto b){ return a < b ? a = b, 1 : 0; }
int main(){
    cin.tie(0)->sync_with_stdio(0);

	int n, m; cin >> n >> m;
	ll ans = 0;
	for (int i=1;i<=n;i++){
		ll tmp = (ll)m*i;
		int x=i;
		while(x>0){
			int v=i/x;
			int y=i/(v+1);

			int l=min(m,y)+1;
			int r=min(m,x)+1;
			tmp -= (ll)v*((ll)r*(r-1)/2-(ll)l*(l-1)/2);
			x=y;
		}
		chmax(ans,tmp);
	}
	cout << ans << '\n';
}