#!/usr/bin/env perl

use strict;
use warnings;
use bigint;

sub sieve {
  my $n = shift;
  my @is_prime;
  push @is_prime, 1 for (0..$n);
  my @ret;
  $is_prime[0] = $is_prime[1] = 0;
  for my $i (2..$n) {
    if ($is_prime[$i]) {
      push @ret, $i;
      for (my $j = 2*$i; $j <= $n; $j += $i) {
        $is_prime[$j] = 0;
      }
    }
  }
  @ret;
}

my ($n, $l) = split / /, <>;
my @primes = sieve(int($l/($n-1)));
my $m = 0;
for (my $i = 0; $i < scalar @primes; $i++) {
  my $cand = $l - $primes[$i] * ($n - 1) + 1;
  $m += $cand if $cand > 0;
}
print $m;