#!/bin/python3

import sys

def maximumValue(a):
    # Return the maximum value of f among all subsegments [l..r].
    lgcd = []
    for x in range(len(a)):
        for y in range(len(a)):
            if a[x] > a[y]:
                smaller = a[y]
            else:
                samller = a[x]
        for i in range(1, smaller+1):
            if((x % i == 0) and (y % i == 0)):
                gcd = i
                lgcd.append(gcd)
    lsum = []
    lmax = []
                
    for i in range(len(a)):
        for j in range(len(a)):
            sum = a[i] + a[j]
            maxi = max(a[i],a[j])
            lsum.append(sum)
            lmax.append(maxi)
    f = list((lgcd*lsum)-lmax)
    return max(f)
            
            

if __name__ == "__main__":
    n = int(input().strip())
    a = list(map(int, input().strip().split(' ')))
    result = maximumValue(a)
    print(result)