#!/usr/bin/env ruby

require "prime"


def count_seqs(n, l)
    d_max = l / (n - 1)
    if d_max < 2
        return 0
    end
    answer = Prime.each(d_max).map {|d|
        l - (n - 1) * d + 1
    }.inject(:+)
    return answer
end


n, l = gets.split.map(&:to_i)
puts count_seqs(n, l)