#include<bits/stdc++.h>
using namespace std;

bool isPrime(long long a){
  if(a == 2)return true;
  if(a < 2 || a % 2 == 0)return false;
  int i = 3;
  while(i <= sqrt((double)a)){
    if(a % i == 0)return false;
    i += 2;
  }
  return true;
}

int main(){
  long long n, l;
  cin >> n >> l;
  long long maxspace = l / (n - 1);
  long long count = 0;
  for(int i = 2; i <= maxspace; i++){
    if(isPrime(i) == false) continue;
    if(i * (n - 1) <= l){
      count += (l + 1) - (i * (n - 1));
//      cout << count << endl;
    }else{
      break;
    }
  }
  cout << count << endl;
}