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

int main(void){
    vector<bool> prime(200009,1);
    for(ll i=2;i<200009;i++){
        if(prime[i]==0)continue;
        for(ll j=i+i;j<200009;j+=i)prime[j]=0;
    }
    ll N,M;

    cin>>N>>M;

    for(;prime[N]==0;N--);

    ll ans=0;
    for(ll i=1;i<=M;i++)ans+=N%i;

    cout<<ans<<endl;

    return 0;
}