#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n) - 1; i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r) - 1;i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	long long n, m; cin >> n >> m;
	vector<long long>imos(n + 2);
	rep2(i, 1, m + 1) {
		{
			int val = 1;
			while (true) {
				int l = val * i;
				if (l > n)break;
				int r = min((int)n + 1, l +i);
				imos[l] += val * i;
				imos[r] -= val * i;
				if (r >= n + 1)break;
				val++;
			}
		}
	}
	rep(i, n + 1)imos[i + 1] += imos[i];
	//rep(i, n + 1) cout << i << " " << imos[i] << endl;
	long long ans = 0;
	rep2(i, 1, n + 1) {
		long long val = m * i;
		val -= imos[i];
		chmax(ans, val);
	}
	cout << ans << endl;
	return 0;
}