from math import lcm
from itertools import combinations

N, L, H = map(int, input().split())
CS = list(map(int, input().split()))
L -= 1
AH = 0
AL = 0
t = 1
for i in range(1, N + 1):
    t2 = t * i
    for C in combinations(CS, i):
        m = 1
        for c in C:
            m = lcm(m,c)
        AL += (L // m) * t2
        AH += (H // m) * t2
    t *= -1
print(AH - AL)