#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<stdlib.h>
#include<vector>
#include<string>
#include<sstream>
#include<math.h>
using namespace std;


int main(){

  int n,l;
  cin >> n >> l;

  int MAX = (l/(n-1))+10;
  vector<int> prime(MAX);

  vector<int> p;

  int end=(int)(sqrt((double)MAX));
  int num;

  if( l <= 3 ){
    cout << 0 << endl;
    return 0;
  }

  prime[0]=0;
  for(int i=1;i<MAX;i++){
      prime[i]=1;
  }

  for(int i=0;i<end;i++){
      if(prime[i]==1){
          num=i+1;
          for(int j=num*2-1;j<MAX;j+=num){
              prime[j]=0;
          }
      }
  }

  bool fl = false;
  for(int i=0;i<MAX;i++){
      if(prime[i]==1){
          p.push_back(i+1);
          fl = true;
      }
  }

  if(fl == false){
    cout << 0 << endl;
    return 0;
  }


  long long int cnt = 0;

  for(int i=0;i<p.size();i++){
    int tmp = l - (p[i]*(n-1));
    if( tmp < 0 ) continue;
    cnt += tmp+1;
  }

  cout << cnt << endl;



  return 0;
}