#include "bits/stdc++.h"

using namespace std;

struct unionfind
{
	//rankのオーバーフローに注意
	vector<int> par, rank;
	unionfind(int n)
	{
		par.resize(n);
		rank.resize(n);
		for (int i = 0; i < n; i++)
		{
			par[i] = i;
			rank[i] = 1;
		}
	}

	bool same(int u, int v)
	{
		return root(u) == root(v);
	}

	void unite(int u, int v)
	{
		u = root(u), v = root(v);
		if (u == v)
			return;
		if (rank[u] > rank[v])
			swap(u, v);
		par[u] = v;
		rank[v] += rank[u];
	}

	int root(int v)
	{
		if (par[v] == v)
			return v;
		return par[v] = root(par[v]);
	}
};

void solve(void)
{
	int n, p;
	cin >> n >> p;
	unionfind uf(n);
	for (int i = 2; i <= n; i++)
	{
		int x = i;
		for (int f = 2; f * f <= x; f++)
		{
			if (x % f == 0)
			{
				uf.unite(f-1, i-1);
			}
			while(x % f == 0)
			{
				x /= f;
			}
		}
		if (x > 1)
		{
			uf.unite(x-1, i-1);
		}
	}
	cout << uf.rank[uf.root(p - 1)] << endl;
}

int main()
{
	solve();
	//cout << "yui(*-v・)yui" << endl;
	return 0;
}