using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, m) = (c[0], c[1]);
        var dp = new long[n + 1];
        for (var i = 1; i <= n; ++i) dp[i] = i * (m - 1L);
        var cum = new long[n + 1];
        for (var i = 2; i <= m; ++i)
        {
            for (var j = i; j <= n; j += i) cum[i] -= i;
        }
        for (var i = 2; i <= n; ++i) cum[i] += cum[i - 1];
        --cum[1];
        for (var i = 1; i <= n; ++i) dp[i] += cum[i];
        WriteLine(dp.Max());
    }
}