#pragma region
#pragma GCC target("avx2")
#pragma GCC optimize("03")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std; typedef long double ld; typedef long long ll;
typedef unsigned long long ull;
#define endl "\n"
#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define rep(i,n) for(int i=0;i<(n);i++)
#define PII pair<int, int>
#define PLL pair<ll, ll>
#define ALL(x) (x).begin(), (x).end()
constexpr int INF=1<<30; constexpr ll LINF=1LL<<60; constexpr ll mod=1e9+7; constexpr int NIL = -1;
template<class T>inline bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>inline bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
#pragma endregion
//-------------------
class UnionFind {
private:
	unsigned size_; std::vector<int> par, rank; //par = root? -size: par 
public:
	UnionFind() : size_(0), par(std::vector<int>()), rank(std::vector<int>()) {};
	UnionFind(unsigned size__) : size_(size__) {
		par.resize(size_+1); rank.resize(size_+1);
		for (unsigned i = 0; i <= size_; i++) par[i] = -1, rank[i] = 0;
	}
	//unsigned size() { return size_; }
	unsigned root(unsigned x) {return par[x] < 0 ? x : par[x] = root(par[x]); }
	bool same(unsigned x, unsigned y) { return root(x) == root(y); }
	void unite(unsigned x, unsigned y) {
		x = root(x), y = root(y);
		if (x == y) return;
		if (rank[x] < rank[y])par[y] += par[x], par[x] = y;
		else if (rank[x] == rank[y])par[x] += par[y], par[y] = x, rank[x]++;
		else par[x] += par[y], par[y] = x;
	}
	int size(int x){ return -par[root(x)];} 
	bool operator==(const UnionFind &u) { return par == u.par; }
	bool operator!=(const UnionFind &u) { return par != u.par; }
};

int main(){
    cin.tie(0); ios::sync_with_stdio(false); //cout << fixed << setprecision(15);
    int n,p; cin >> n >> p;
    
    UnionFind uf(n);
    
    vector<bool> isprime(n+1, true);
    for(int i=2; i<=n; i++) {
        if(isprime[i]) {
            for(int j=2*i; j<=n; j+=i) {
                isprime[j] = false;
                uf.unite(i, j);
            }
        }
    }

    cout << uf.size(p) << endl;

    return 0;
}