N, L, H = gets.split.map(&:to_i)
C = gets.split.map(&:to_i)
ans = 0

1.upto(N) do |n|
  C.combination(n) do |nums|
    l = nums.inject(:lcm)
    cnt = H / l - (L - 1) / l

    if n.even?
      ans -= n * cnt
    else
      ans += n * cnt
    end
  end
end

puts ans