#include<iostream>
#include<cstdio>
#include<cstring>
#include <cstdlib>  
#include <math.h>
#include <cmath>
#include<cctype>
#include<string>
#include<set>
#include<iomanip>
#include <map>
#include<algorithm>
#include <functional>
#include<vector>
#include<climits>
#include<stack>
#include<queue>
#include <deque>
#include <climits>
#include <typeinfo>
#include <utility> 
#define all(x) (x).begin(),(x).end()
#define rep(i,m,n) for(int i = m;i < n;++i)
#define pb push_back
#define fore(i,a) for(auto &i:a)
#define rrep(i,m,n) for(int i = m;i >= n;--i)
#define INF INT_MAX/2
using namespace std;
using ll = long long;
using R = double;
using Data = pair<ll, vector<int>>;
const ll MOD = 1e9 + 7;
const ll inf = 1LL << 50;
struct edge { ll from; ll to; ll cost; };
typedef tuple<ll, ll, ll>T;
typedef pair<ll,ll>pll;

vector<int>dv;

class UnionFind {
public:
	vector<int> s, p;

	UnionFind() {}
	UnionFind(int size) {
		s.resize(size, 0);
		p.resize(size, 0);
		rep(i, 0, size)makeSet(i);
	}

	void makeSet(int x) {
		p[x] = x;
		s[x] = 1;
	}

	bool same(int x, int y) {
		return findSet(x) == findSet(y);
	}

	void unite(int x, int y) {
		x = findSet(x);
		y = findSet(y);

		if (x == y)return;

		if (s[x] < s[y])swap(x, y);

		p[y] = x;
		s[x] += s[y];
	}


	int findSet(int x) {
		if (x == p[x]) {
			return x;
		}
		else {
			return p[x] = findSet(p[x]);
		}
	}

	int size(int x) {
		return s[findSet(x)];
	}
};

void divisor(ll n) {
	dv.erase(all(dv));
	for (ll i = 1; i*i <= n; i++) {
		if (n%i == 0) {
			if (i == n / i) {
				dv.push_back(i);
			}
			else {
				dv.push_back(i);
				dv.push_back(n / i);
			}
		}
	}
}

int main(){
	int n, p;
	cin >> n >> p;
	UnionFind un = UnionFind(n);
	
	vector<int>li(1010101);
	rep(i, 0, n + 1)li[i] = 1;
	li[0] = li[1] = 0;
	for (int i = 2; i <= n; i++) {
		if (li[i]) {
			for (int j = 2 * i; j <= n; j += i) {
				li[j] = 0;
				un.unite(i-1,j-1);
			}
		}
	}
	cout << un.size(p - 1) << endl;

	return 0;
}