N = int(eval(input()))

A =list(map(int, input().split()))

minus = [i for i in A if i < 0]

if len(minus) % 2 == 0:

  max_num = [abs(i) for i in A]

  print((sum(max_num)))

else:

  max_num = [abs(i) for i in A]

  if min(max_num) in A:

    print((sum(max_num) - 2*min(max_num)))

  else:

    print((sum(max_num) + -(2*min(max_num))))
N = int(eval(input()))

A =list(map(int, input().split()))

minus = [i for i in A if i < 0]

if len(minus) % 2 == 0:

  max_num = [abs(i) for i in A]

  print((sum(max_num)))

else:

  max_num = [abs(i) for i in A]

  print((sum(max_num) - (2*min(max_num))))
N = int(eval(input()))
A = list(map(int, input().split()))
minus = [i for i in A if i < 0]
if len(minus) % 2 == 0:
    max_num = [abs(i) for i in A]
    print((sum(max_num)))
else:
    max_num = [abs(i) for i in A]
    if min(max_num) in A:
        print((sum(max_num) - 2 * min(max_num)))
    else:
        print((sum(max_num) + -(2 * min(max_num))))

N = int(eval(input()))
A = list(map(int, input().split()))
minus = [i for i in A if i < 0]
if len(minus) % 2 == 0:
    max_num = [abs(i) for i in A]
    print((sum(max_num)))
else:
    max_num = [abs(i) for i in A]
    print((sum(max_num) - (2 * min(max_num))))

-    if min(max_num) in A: -        print((sum(max_num) - 2 * min(max_num))) -    else: -        print((sum(max_num) + -(2 * min(max_num)))) +    print((sum(max_num) - (2 * min(max_num))))