import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    long l = sc.nextLong();
    int t = (int)l / (n - 1);
    ArrayList<Long> prime = new ArrayList<Long>();
    boolean[] is_prime = new boolean[t + 1];
    for(int i = 0; i <= t; i++) is_prime[i] = true;
    is_prime[0] = false;
    is_prime[1] = false;
    for(int i = 2; i <= t; i++) {
      if(is_prime[i]) {
        prime.add((long)i);
        for(int j = 2 * i; j <= t; j += i) is_prime[j] = false;
      }
    }
    long ans = 0;
    for(int i = 0; i < prime.size(); i++) {
      long p = prime.get(i);
      ans += (l - p * (long)(n - 1));
    }
    System.out.println(ans);    
  }
}