output_description: Print the minimum time required to light K candles.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N K
      x_1 x_2 ... x_N
attempt: N, K = map(int, input().split(" "))
  Xs = [int(a) for a in input().split()]
  
  
  min = 3 * (10**8)
  
  p = 0
  z = 0
  m = 0
  Y = []
  for x in Xs:
      if x > 0:
          p += 1
          Y.append(x)
      elif x < 0:
          m += 1
      else:
          z += 1
  
  
  K -= z
  Z = []
  for i in range(m - 1, -1, -1):
      Z.append(-Xs[i])
  
  
  if K == 0:
      min = 0
  if K - 1 < p and K - 1 >= 0:
      if Y[K - 1] < min:
          min = Y[K - 1]
  
  if K - 1 < m and K - 1 >= 0:
      if Z[K - 1] < min:
          min = Z[K - 1]
  
  for i in range(p):
      if i < K - 1:
          if K - i - 2 < m:
              if Y[i] * 2 + Z[K - i - 2] < min:
                  min = Y[i] * 2 + Z[K - i - 2]
  
  for i in range(m):
      if i < K - 1:
          if K - i - 2 < p:
              if Z[i] * 2 + Y[K - i - 2] < min:
                  min = Z[i] * 2 + Y[K - i - 2]
  
  
  print(min)
  
problem_description: Statement
  
  There are N candles placed on a number line. The i-th candle from the left is
  placed on coordinate x_i. Here, x_1 < x_2 < ... < x_N holds.
  
  Initially, no candles are burning. Snuke decides to light K of the N candles.
  
  Now, he is at coordinate 0. He can move left and right along the line with
  speed 1. He can also light a candle when he is at the same position as the
  candle, in negligible time.
  
  Find the minimum time required to light K candles.
samples: [{"input": "5 3\n    -30 -10 10 20 50", "output": "40\n    \n\nHe should move and light candles as follows:\n\n  * Move from coordinate 0 to -10.\n  * Light the second candle from the left.\n  * Move from coordinate -10 to 10.\n  * Light the third candle from the left.\n  * Move from coordinate 10 to 20.\n  * Light the fourth candle from the left.\n\n* * *"}, {"input": "3 2\n    10 20 30", "output": "20\n    \n\n* * *"}, {"input": "1 1\n    0", "output": "0\n    \n\n  * There may be a candle placed at coordinate 0.\n\n* * *"}, {"input": "8 5\n    -9 -7 -4 -3 1 2 3 4", "output": "10"}]