def max_product(nums):
    min1 = min2 = float('inf')
    max1 = max2 = max3 = float('-inf')

    for num in nums:
        if num < min1:
            min2 = min1
            min1 = num
        elif num < min2:
            min2 = num

        if num > max1:
            max3 = max2
            max2 = max1
            max1 = num
        elif num > max2:
            max3 = max2
            max2 = num
        elif num > max3:
            max3 = num

    return max(max1 * max2 * max3, min1 * min2 * max1)

n = int(input())
nums = list(map(int, input().split()))
print(max_product(nums))