N = int(input())
C = list(map(int, input().split())) 
C.sort()
A=0
B=0
if sum(C)>=0:
    C=C[::-1]
    for i in range(N):
        if i%2==0:
            A+=C[i]
        else:
            B+=C[i]
else:
    for i in range(N):
        if i%2==0:
            A+=C[i]
        else:
            B+=C[i]

print(min(max(abs(abs(sum(C[N//2+1:]))-abs(sum(C[:N//2+1]))),
          abs(abs(sum(C[N//2:]))-abs(sum(C[:N//2])))),
          abs(A)-abs(B)))