def gcc(x, y):
    x=abs(x)
    y=abs(y)
    while(y):
        x, y = y, x%y
    return x
n = int(input().strip())
lr=0
arr = list(map(int, input().strip().split(' ')))
for i in range(n):
    for j in range(n):
        aa = ((arr[i]+arr[j])-max(arr[i],arr[j]))*gcc(arr[i],arr[j])
        if aa>lr:
            lr=aa
print(lr)