#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 1000000000000000000

bool is_prime[10000010];
int primes[2000000];

void setPrime() {
	for (int i = 2; i <= 10000000; i++) is_prime[i] = true;
	for (int i = 2; i <= 10000000; i++) {
		if (is_prime[i]) {
			for (int j = i * 2; j <= 10000000; j += i) {
				is_prime[j] = false;
			}
		}
	}

	int id = 0;
	for (int i = 2; i <= 10000000; i++) {
		if (is_prime[i]) primes[id++] = i;
	}
}
int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
	int N, L;
	cin >> N >> L;
	setPrime();
	ll ans = 0;
	int i = 0;
	while(true) {
		int add = L - primes[i++] * (N - 1) + 1;
		if (add > 0)
			ans += add;
		else break;
		//cout << primes[i] << " " << ans << endl;
	}
	cout << ans << endl;



    return 0;
}