#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
    int n,l;
    cin>>n>>l;
    int d=l/(n-1);
    bool prime[d+1];
    fill(prime,prime+d+1,1);
    prime[0]=prime[1]=0;
    for (int i=2;i*i<=d;i++) {
        if (!prime[i]) continue;
        for (int j=i+i;j<=d;j+=i)
            prime[j]=0;
    }
    ll ans=0;
    for (int i=2;i<=d;i++) {
        if (!prime[i]) continue;
        ans+=l-(n-1)*i+1;
    }
    cout<<ans<<endl;
    return 0;
}