#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using ll =  long long ;
using P = pair<ll,ll> ;
const int INF = 1e9;
const int MOD = 1000000007;

ll gcd(ll i,ll j){
        if(j == 0) return i;
        return gcd(j,i%j);
}

struct Unionfind{
    vector<int> parents;
    int m;
    Unionfind(int n):parents(n,-1){
        m = n;
    }

    int find(int x){
        if(parents.at(x) < 0){
            return x;
        }else{
            parents.at(x) = find(parents.at(x));
            return parents.at(x);
        }
    }

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

        if(x==y) return;
        if(parents.at(x) > parents.at(x))swap(x,y);
        parents.at(x) += parents.at(y);
        parents.at(y) = x;
    }  

   int size(int x){
       return -parents.at(find(x));
   }

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

   vector<int> members(int x){
       int root = find(x);
       vector<int> A;
       for(int i=0;i<m;i++){
           if(find(i) ==root ){
               A.push_back(i);
           }
       }
      return A;
  }
};

int main(){
    int n,p;
    cin >> n >> p;
    Unionfind uf(n+5);
    vector<int> f(n+5,0);
    f[0] = f[1] = -1;
    for(int i=2;i<=n;i++){
        if(f[i]) continue;
        for(int j=i;j<=n;j+=i){
            f[j] = i;
            if(j==i) continue;
            uf.unite(j,j-i);
        }
    }
    cout << uf.size(p) << endl;
    return 0;
}