#include //#include using namespace std; // using namespace atcoder; // using mint = modint1000000007; // const int mod = 1000000007; // using mint = modint998244353; // const int mod = 998244353; // const int INF = 1e9; // const long long LINF = 1e18; #define rep(i, n) for (int i = 0; i < (n); ++i) #define rep2(i, l, r) for (int i = (l); i < (r); ++i) #define rrep(i, n) for (int i = (n)-1; i >= 0; --i) #define rrep2(i, l, r) for (int i = (r)-1; i >= (l); --i) #define all(x) (x).begin(), (x).end() #define allR(x) (x).rbegin(), (x).rend() #define P pair template inline bool chmax(A &a, const B &b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(A &a, const B &b) { if (a > b) { a = b; return true; } return false; } #ifndef KWM_T_MATH_SIEVE_HPP #define KWM_T_MATH_SIEVE_HPP #include namespace kwm_t::math { /** * @brief エラトステネスの篩(bool版) * is_prime[i] を返す */ inline std::vector sieve(int n) { std::vector is_prime(n + 1, true); if (n >= 0) is_prime[0] = false; if (n >= 1) is_prime[1] = false; for (int p = 2; p * p <= n; ++p) { if (!is_prime[p]) continue; for (int i = p * p; i <= n; i += p) { is_prime[i] = false; } } return is_prime; } /** * @brief 素数列挙 * sieve を利用して primes を返す */ inline std::vector primes(int n) { auto is_prime = sieve(n); std::vector res; for (int i = 2; i <= n; ++i) { if (is_prime[i]) res.push_back(i); } return res; } } #endif int main() { std::ios::sync_with_stdio(false); std::cin.tie(nullptr); int n, l; cin >> n >> l; auto ps = kwm_t::math::primes(l); long long ans = 0; for (auto p : ps) { long long x = (long long)p *(n - 1); if (x > l)continue; ans += l - x + 1; } cout << ans << endl; return 0; }