import math
N,L,H=map(int,input().split())
C=list(map(int,input().split()))
import itertools
def comb(N,C):
    return math.factorial(N)//(math.factorial(C)*math.factorial(N-C))
def lcm(leng,l):
    if leng==1:
        return l[0]
    lcm_all=l[0]
    for _ in range(leng-1):
        lcm_all=lcm_all*l[_+1]//math.gcd(lcm_all,l[_+1])
    return lcm_all
ans=0
for i in range(1,N+1):
    for j in itertools.combinations(C,i):
        tmp=lcm(len(j),j)
        if i%2==0:
            ans-=(H//tmp-(L-1)//tmp)*i
        else:
            ans+=(H//tmp-(L-1)//tmp)*i
print(ans)