a,b=gets.split.map{|x|x.to_i}
t = [true] * (b + 1)
for i in (2..b) do
  break if i * i > b 
  (i+i).step(b, i) do |j|
    t[j] = false
  end
end
ans = 0
def f(x)
  return x*x*x-x*x+x+1
end
a.upto(b) do |x|
  ans += f(x) if t[x]
end
puts ans