import numpy as np



N = int(eval(input()))

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



A2 = np.abs(A)

x = A2.min()

s = A2.sum()

A3 = A < 0

if sum(A3) % 2 == 0:

    print(s)

else:

    print((s-2*x))



import numpy as np



N = int(eval(input()))

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



A2 = np.abs(A)

x = A2.min()

s = A2.sum()

A3 = A < 0

if A3.sum() % 2 == 0:

    print(s)

else:

    print((s-2*x))



import numpy as np

N = int(eval(input()))
A = np.array(list(map(int, input().split())))
A2 = np.abs(A)
x = A2.min()
s = A2.sum()
A3 = A < 0
if sum(A3) % 2 == 0:
    print(s)
else:
    print((s - 2 * x))

import numpy as np

N = int(eval(input()))
A = np.array(list(map(int, input().split())))
A2 = np.abs(A)
x = A2.min()
s = A2.sum()
A3 = A < 0
if A3.sum() % 2 == 0:
    print(s)
else:
    print((s - 2 * x))

-if sum(A3) % 2 == 0: +if A3.sum() % 2 == 0: