#include using namespace std; #define rep(i,n) REP(i,0,n) #define REP(i,s,e) for(int i=(s); i<(int)(e); i++) #define repr(i, n) REPR(i, n, 0) #define REPR(i, s, e) for(int i=(int)(s-1); i>=(int)(e); i--) #define pb push_back #define all(r) r.begin(),r.end() #define rall(r) r.rbegin(),r.rend() #define fi first #define se second typedef long long ll; typedef vector vi; typedef vector vl; typedef pair pii; typedef pair pll; const int INF = 1e9; const ll MOD = 1e9 + 7; double EPS = 1e-8; struct UFT{ //O(loga(n)) int n; vi d, r; UFT(int n) : n(n), d(n, -1), r(n, 0){}; int root(int i){ if(d[i] < 0) return i; return d[i] = root(d[i]); } bool same(int x, int y){ return root(x) == root(y); } bool unite(int x, int y){ x = root(x); y = root(y); if(x == y) return false; if(r[x] < r[y]) swap(x, y); else if(r[x] == r[y]) r[x]++; d[x] += d[y]; d[y] = x; return true; } int size(int i){ return -d[root(i)]; } }; int main(){ int n, p; cin >> n >> p; UFT uf(n+1); REP(i, 2, n+1){ for(int j = i+i; j <= n; j += i) { uf.unite(i, j); } } cout << uf.size(p) << endl; return 0; }