#!/bin/python

import sys
from itertools import permutations


def gcd(a, b):
    if not b:
        return a
    else:
        return gcd(b, a % b)

def gcd_n(numbers):
    return reduce(lambda x, y: gcd(x, y), numbers)


def maximumValue(a):
    arr=[]
    mm= list(list(permutations(a,2))[0])
    for i in list(permutations(a,2)):
        arr.append((sum(i)-max(i))*abs(gcd_n(i)))
    return max(arr)
    # Return the maximum value of f among all subsegments [l..r].

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