#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;
using ll = long long;

int main()
{
    ll n, l, max = 0, MAX = 1e7+1;
    ll ans = 0;
    cin >> n >> l;
    vector<ll> p(MAX, 1);
    p[0] = 0;
    p[1] = 0;
    for (int i = 2; i < MAX; i++){
        for (int j = i*2; j < MAX; j += i){
            p[j] = 0;
        }
    }
    max = 2*(n-1);
    if ((l - max + 1) > 0) ans += (l - max + 1);
    for (ll i = 3; i*(n-1) < MAX; i+=2){
        if (p[i]) {
            max = i*(n-1);
            if ((l - max + 1) > 0) ans += (l - max + 1);
        }
    }
    cout << ans << endl;
}