#include <bits/stdc++.h>

using ll = std::int64_t;

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int N, M;
    std::cin >> N >> M;

    ll res = 0;
    for(int i=1;i<=N;i++){
        ll sum = 1ll * i * M;

        int q = i / M;
        int r = M;
        int l = i / (q + 1);
        while(true){
            sum -= 1ll * (l + 1 + r) * (r - l) / 2 * q;
            if(l == 0){break;}
            q = i / l;
            r = l;
            l = i / (q + 1);
        }

        res = std::max(res, sum);
    }

    std::cout << res << std::endl;
}