a = input()
a = list(a.split(' '))
a = list(map(int, a))

even = 0
odd = 0
minus = 0

for item in a:
    if item < 0:
        minus = minus + 1
        
    if item % 2 == 0:
        even = even + 1
        
    else:
        odd = odd + 1
        
if even < 2 or odd < 2 or minus > 3:
    print(max(a))
    
else:
    print(min(a))