#include<bits/stdc++.h>
using namespace std;
#define rep(i,N) for(i=0;i<N;i++)
#define ll long long

int main(void){
    ll i,j,k;
    ll N,M;

    cin>>N>>M;

    vector<bool> is_prime(200009,1);
    set<ll>prime;
    for(ll i=2;i<200009;i++){
        if(is_prime[i]==0)continue;
        prime.insert(i);
        for(ll j=i+i;j<200009;j+=i)is_prime[j]=0;
    }

    ll now=0;
    ll ans=0;
    for(ll i=1;i<=N;i++){
        now+=M;
        ll erase=1;
        ll k=i;
        for(auto it=prime.begin();it!=prime.end();it++){
            if(k==1)break;
            if(prime.find(k)!=prime.end()){
                erase*=k+1;
                break;
            }
            ll mul=1;
            ll power=1;
            while(k%*it==0){
                k/=*it;
                power*=*it;
                mul+=power;
            }
            erase*=mul;
        }
        now-=erase;
        ans=max(ans,now);
    }

    cout<<ans<<endl;

    return 0;
}