#include <atcoder/all>
#include <bits/stdc++.h>
#define rep(i, a, b) for (ll i = (ll)(a); i < (ll)(b); i++)
using namespace atcoder;
using namespace std;

typedef long long ll;

int main() {
    int n, m;
    cin >> n >> m;

    auto f = [&](int x) {
        if (!(1 <= x && x <= n))
            return 0LL;
        ll ret = 0;
        rep(i, 1, m + 1) { ret += x % i; }
        return ret;
    };

    ll ans = 0;
    ans = max(ans, f(1));
    ans = max(ans, f(2));
    ans = max(ans, f(3));
    ans = max(ans, f(n - 1));
    ans = max(ans, f(n + 0));
    ans = max(ans, f(n + 1));
    ans = max(ans, f(m - 1));
    ans = max(ans, f(m + 0));
    ans = max(ans, f(m + 1));
    cout << ans << endl;
}