#include #define rep(i,a,b) for(int i=a;i=b;i--) #define fore(i,a) for(auto &i:a) #define all(x) (x).begin(),(x).end() //#pragma GCC optimize ("-O3") using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); } typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60; templatebool chmax(T &a, const T &b) { if (abool chmin(T &a, const T &b) { if (b ED[1010101]; int B[1010101]; void init() { rep(i, 1, N + 1) B[i] = i; rep(d, 2, N + 1) for (int x = d; x <= N; x += d) ED[x].push_back(x); } //--------------------------------------------------------------------------------------------------- void _main() { cin >> N >> P; init(); int ans = 0; queue que; vis[P] = 1; que.push(P); while (!que.empty()) { int cu = que.front(); que.pop(); ans++; fore(d, ED[cu]) if (!vis[d]) { vis[d] = 1; que.push(d); } for (int x = cu; x <= N; x += cu) if (!vis[x]) { vis[x] = 1; que.push(x); } } cout << ans << endl; }