output_description: Print an integer denoting the answer.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      N E T
      x_1 x_2 ... x_N
attempt: import sys
  
  
  def solve(n, e, t, xxx):
      if n == 1:
          return e + t
  
      ans = xxx[0] + (e - xxx[-1])
  
      i = 0
      while i < n:
          for j in range(i, n - 1):
              dx0 = xxx[j] - xxx[i]
              dx1 = xxx[j + 1] - xxx[i]
              stop = max(2 * dx0, t) + dx0 + xxx[j + 1] - xxx[j] + t
              through = max(2 * dx1, t) + dx1
              if stop < through:
                  ans += stop - t
                  i = j + 1
                  break
          else:
              dx1 = xxx[n - 1] - xxx[i]
              ans += max(2 * dx1, t) + dx1
              i = n
  
      return ans
  
  
  n, e, t, *xxx = map(int, sys.stdin.buffer.read().split())
  print(solve(n, e, t, xxx))
  
problem_description: Statement
  
  Imagine a game played on a line. Initially, the player is located at position
  0 with N candies in his possession, and the exit is at position E. There are
  also N bears in the game. The i-th bear is located at x_i. The maximum moving
  speed of the player is 1 while the bears do not move at all.
  
  When the player gives a candy to a bear, it will provide a coin after T units
  of time. More specifically, if the i-th bear is given a candy at time t, it
  will put a coin at its position at time t+T. The purpose of this game is to
  give candies to all the bears, pick up all the coins, and go to the exit. Note
  that the player can only give a candy to a bear if the player is at the exact
  same position of the bear. Also, each bear will only produce a coin once. If
  the player visits the position of a coin after or at the exact same time that
  the coin is put down, the player can pick up the coin. Coins do not disappear
  until collected by the player.
  
  Shik is an expert of this game. He can give candies to bears and pick up coins
  instantly. You are given the configuration of the game. Please calculate the
  minimum time Shik needs to collect all the coins and go to the exit.
samples: [{"input": "3 9 1\n    1 3 8", "output": "12\n    \n\nThe optimal strategy is to wait for the coin after treating each bear. The\ntotal time spent on waiting is 3 and moving is 9. So the answer is 3 + 9 = 12.\n\n* * *"}, {"input": "3 9 3\n    1 3 8", "output": "16\n    \n\n* * *"}, {"input": "2 1000000000 1000000000\n    1 999999999", "output": "2999999996"}]