import math

n = int(input())
l = list(map(int,input().split()))

def lcm(a, b):
    return int(a * b / math.gcd(a, b))

llcm=1
for i in range(n):
    llcm= lcm(llcm,l[i])

mmax=llcm
fmmax=0
for m in range(mmax):
    fm=0
    for i in l:
        fm += m%i
    if fm > fmmax:
        fmmax=fm
print(fmmax)