two max number multiplication

import random

MIN_ARRAY_LENGTH = 1
MAX_ARRAY_LENGTH = 50
MIN_NUM = 0
MAX_NUM = 100

# Uses python3
def max_mult(a,n):
	if n < 1:
		return 0
	if n < 2:
		return a[0]
	if n < 3:
		return a[0] * a[1]

	max1_idx = 0
	for i in range(0, n):
		if a[max1_idx] < a[i]:
			max1_idx = i

	max2_idx = 1 if max1_idx == 0 else 0
	for i in range(0, n):
		if  a[max2_idx] < a[i] and i != max1_idx:
			max2_idx = i

	return a[max1_idx] * a[max2_idx]


def max_mult_test(a,n):
	if n < 1:
		return 0
	if n < 2:
		return a[0]
	if n < 3:
		return a[0] * a[1]

	result = 0
	max1_idx = 0
	max2_idx = 0

	for i in range (0, n):
		for j in range (i+1, n):
			_result = a[i] * a[j]
			if _result > result:
				result = _result
				max1_idx = i
				max2_idx = j
	return a[max1_idx] * a[max2_idx]

def rand_array(n):
	return [random.randint(MIN_NUM, MAX_NUM) for i in range(n)]

n = int(input())
a = [int(x) for x in input().split()]
assert(len(a) == n)

# i = 0
# while True:
# 	i += 1
# 	print("\n-- #" + str(i) + " --\n")
# 	n = random.randint(MIN_ARRAY_LENGTH, MAX_ARRAY_LENGTH)
# 	a = rand_array(n)
# 	result1 = max_mult(a,n)	
# 	result2 = max_mult_test(a,n)	
# 	if result1 != result2:
# 		print("Array: " +  ' '.join(str(e) for e in a) )
# 		print("Got: " + str(result1) )
# 		print("Stress test: " + str(result2) )
# 		print("\n")
# 		break

result = max_mult(a,n)
print(result)
# result = max_mult_test(a,n)
# print(result)