题解 | #最大乘积#

import sys

leng = int(sys.stdin.readline())
a1=0
a2=0
a3=0
b1=0
b2=0
b3=0
l= []
arr = sys.stdin.readline().split()
# print(leng,arr)
for i in arr:
    if int(i)>0:
        if int(i)**2 >a1**2:
            a3=a2
            a2=a1
            a1=int(i)
    
        elif int(i)**2 >a2**2:
            a3=a2
            a2=int(i)
            
        elif int(i)**2 >a3**2:
            a3=int(i)
    
    if int(i)<0:
        if int(i)**2 >b1**2:
            b3=b2
            b2=b1
            b1=int(i)
    
        elif int(i)**2 >b2**2:
    
            b3=b2
            b2=int(i)
            
        elif int(i)**2 >b3**2:
            b3=int(i)
    # print(a1,a2,a3,l)
m1 = a1*a2*a3
m2=b1*b2*a1
if m1>m2:
    print(m1)
else:
    print(m2)