#include using namespace std; #define FOR(i,a,b) for(int i=(a);i<(b);i++) #define REP(i,n) FOR(i,0,n) #define ALL(v) (v).begin(),(v).end() template inline bool chmax(A &a, B b) { if (a inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; } typedef unsigned long long ull; typedef long long ll; typedef pair pii; typedef pair pll; typedef pair P; const ll INF = 1ll<<29; const ll MOD = 1000000007; const double EPS = 1e-10; vector sieve(int n) { vector res; vector is_prime(n + 1, true); is_prime[0] = is_prime[1] = false; for (int i = 2; i * i <= n; i++) if (is_prime[i]) { res.push_back(i); is_prime[i] = false; for (int j = 2; i * j <= n; j++) if (is_prime[i * j]) { is_prime[i * j] = false; } } REP(i, n + 1) if (is_prime[i]) res.push_back(i); sort(res.begin(), res.end()); return res; } int main() { int n, l; cin >> n >> l; vector prime = sieve(l / 2 + 1); ll ans = 0; REP(i, prime.size()) { ll last = (ll)prime[i] * (n - 1); if (last > l) break; ans += l - last + 1; } cout << ans << endl; return 0; }