import sys
input = sys.stdin.readline

N=int(input())
A=list(map(int,input().split()))
S=sum(A)

U=[0]*(5*10**5+1)
for a in A:
    U[a]+=1

from itertools import accumulate
ACC=list(accumulate(U))

ANS=0

for i in range(5*10**5+1):
    if U[i]==0:
        continue

    ANS+=S*U[i]
    for j in range(i+i-1,5*10**5+1,i):
        ANS-=U[i]*i*(ACC[j]-ACC[j-i])*(j//i)

print(ANS)