N,L,H = list(map(int, input().split(' ')))
CS = list(map(int, input().split(' ')))

from functools import reduce
from fractions import gcd
from itertools import combinations

def lcm(*numbers):
    def lcm(a, b):
        return (a * b) // gcd(a, b)
    return reduce(lcm, numbers, 1)

def pie(n, cs):
    total = 0
    for i in range(1, len(cs)+1):
        for c in combinations(cs, i):
            total += pow(-1, i-1) * i * (n//lcm(*c))
    return total

print(pie(H, CS) - pie(L-1, CS))