#include #include #include #include #include #include #include #include #include #include #include static const int MOD = 1000000007; using ll = long long; using u32 = uint32_t; using namespace std; template constexpr T INF = ::numeric_limits::max()/32*15+208; class UnionFind { int n; vector uni; public: explicit UnionFind(int n) : uni(static_cast(n), -1) , n(n){}; int root(int a){ if (uni[a] < 0) return a; else return (uni[a] = root(uni[a])); } bool unite(int a, int b) { a = root(a); b = root(b); if(a == b) return false; if(uni[a] > uni[b]) swap(a, b); uni[a] += uni[b]; uni[b] = a; return true; } int size(int i){ return -uni[root(i)]; } bool same(int a, int b) { return root(a) == root(b); } }; int main() { int n, p; cin >> n >> p; UnionFind uf(n); for (int i = 2; i <= n; ++i) { for (int j = i*2; j <= n; j += i) { uf.unite(i-1, j-1); } } cout << uf.size(p-1) << "\n"; return 0; }