#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } const long long MAX = 5100000; const long long INF = 1LL << 60; const long long mod = 1000000007LL; //const long long mod = 998244353LL; using namespace std; typedef unsigned long long ull; typedef long long ll; bool IsPrime[MAX]; ll MinFactor[MAX]; vector preprocess(ll n = MAX) { vector res; for (ll i = 0; i < n; ++i) IsPrime[i] = true, MinFactor[i] = -1; IsPrime[0] = false; IsPrime[1] = false; MinFactor[0] = 0; MinFactor[1] = 1; for (ll i = 2; i < n; ++i) { if (IsPrime[i]) { MinFactor[i] = i; res.push_back(i); for (ll j = i * 2; j < n; j += i) { IsPrime[j] = false; if (MinFactor[j] == -1) MinFactor[j] = i; } } } return res; } vector > fast_prime_factor(ll n) { vector > res; while (n != 1) { ll prime = MinFactor[n]; ll exp = 0; while (MinFactor[n] == prime) { ++exp; n /= prime; } res.push_back(make_pair(prime, exp)); } return res; } class UnionFind { public: vector Parent; UnionFind(ll N) { Parent = vector(N, -1); } ll root(ll A) { if (Parent[A] < 0) { return A; } return Parent[A] = root(Parent[A]); } ll size(ll A) { return -Parent[root(A)]; } bool connect(ll A, ll B) { A = root(A); B = root(B); if (A == B) { return false; } if (size(A) < size(B)) { swap(A, B); } Parent[A] += Parent[B]; Parent[B] = A; return true; } }; int main() { /* cin.tie(nullptr); ios::sync_with_stdio(false); */ preprocess(); ll N, P; cin >> N >> P; UnionFind uni(N + 1); for (ll i = 2; i <= N; i++) { vector> vp = fast_prime_factor(i); for (auto p : vp) { uni.connect(p.first, i); } } cout << uni.size(P) << endl; return 0; }