import heapq

n = int(input())
A = list(map(int, input().split()))
A = [-a for a in A]
heapq.heapify(A)
while len(A) > 1:
    a1 = heapq.heappop(A)
    a2 = heapq.heappop(A)
    heapq.heappush(A, -a1 * a2)

print(-A[0])