N, L, H = gets.split.map &:to_i
C = gets.split.map &:to_i

def f(l, h, c)
  h/c - (l-1)/c
end

p (1..N).map{|n|
  C.combination(n).map{|a|
    f(L, H, a.inject(:lcm))
  }.sum * n * (n.odd? ? 1 : -1)
}.sum