#include <bits/stdc++.h>
using namespace std;
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define vv(type, c, m, n, i) vector<vector<type>> c(m, vector<type>(n, i))
#define rep(i,a,n) for(int i=(a), i##_len=(n); i<i##_len; ++i)
#define rrep(i,a,n) for(int i=(a), i##_len=(n); i>i##_len; --i)
#define each(x,y) for(auto &(x):(y))
#define len(x) ((int)(x).size())
#define mp make_pair
#define eb emplace_back
#define em emplace
#define pb pop_back
#define fi first
#define se second
#define get(a, i) get<i>(a)
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<long long> vll;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef pair<int, int> pii;
#define mini min_element
#define maxi max_element
#define sum(a, b) accumulate(a, b)
#define chmax(a,b) if(a<b)a=b
#define chmin(a,b) if(a>b)a=b
#define ce(x, y) (x + y - 1) / y
template <class T> inline void print(T t){cout << t << "\n";}
template <class H, class... T> inline void print(H h, T... t){cout << h << " ";print(t...);}
vi ret{2};
void makePrime(int n) {
	vb ok(n, true);
	ret.reserve(n + 1);
	for (int i = 3; i < n; i += 2) {
		int i2 = i / 2;
		if (!ok[i2]) continue;
		ret.eb(i);
		for (int j = i2 + i, n2 = n / 2; j < n2; j += i) ok[j] = false;
	}
}
ll solve() {
	ll n, l; cin >> n >> l;
	if (n * 2 - 1 > l)
		return 0;
	makePrime(l / (n - 1) + 1);
	ll ans = 0;
	rep(i, 0, len(ret)) {
		ans += l - ret[i] * (n - 1) + 1;
	}
	return ans;
}
int main() {
	print(solve());
	return 0;
}