import sys
input = sys.stdin.readline

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

M = max(A)+3

B = [0]*(M+1)
for a in A:
    B[a] += 1

C = [0]*(M+1)
D = [0]*(M+1)
for i in range(M):
    C[i+1] = C[i] + B[i+1]
    if B[i+1] == 1:
        D[i+1] = D[i] + i+1
    else:
        D[i+1] = D[i]

ans = 0
for x in range(1, M):
    if B[x] == 1:
        s = 0
        bucket_num = (M+1)//x
        for b in range(1, bucket_num+1):
            b_cnt = (C[x*(b+1)-1] if x*(b+1)-1 < M+1 else C[M]) - C[x*b-1]
            b_sum = (D[x*(b+1)-1] if x*(b+1)-1 < M+1 else D[M]) - D[x*b-1]
            r = b_cnt * x*(b+1) - b_sum
            s += r
        s -= x
        ans += s

print(ans)