import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


n = int(input())
a = list(map(int, input().split()))
a.sort()
from collections import Counter
c = Counter(a)
ks = list(set(a))
ks.sort()
m = max(a)
l = [0]*(m+1)
ans = 0
prv = 0
count = 0
for k in ks:
    for i in range(prv,k+1):
        l[i] += count
    for i in range(2*k,m+1,k):
        l[i] += -k*c[k]
#     print(l)
    count += c[k]
    prv = k+1
for i in range(1,m+1):
    l[i] = l[i-1] + l[i]
v0 = 0
v1 = 0
for i,v in enumerate(l):
    if i in c:
        v0 += c[i]*v
val = 0
for i in range(m,0,-1):
    if i in c:
        v1 += i*c[i]*val
        val += c[i]
ans = v0 + v1
print(ans)