def main():
  input()
  C = list(map(int, input().split()))
  if C[-1] < 0:
    print(abs(C[0])*2)
  if C[0] < 0 <= C[-1]:
    print(abs(C[0])*2 + abs(C[-1])*2)
  if 0 <= C[0]:
    print(abs(C[-1])*2)

main()