output_description: Let m be the number of operations in your solution. In the first line, print
  m. In the i-th of the subsequent m lines, print the numbers x and y chosen in
  the i-th operation, with a space in between. The output will be considered
  correct if m is between 0 and 2N (inclusive) and a satisfies the condition
  after the m operations.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      a_1 a_2 ... a_{N}
attempt: # 一番絶対値大きいところから
  # 正なら右側に2回足すを繰り返す
  # 負なら左側に2回足すを繰り返す
  # これを行った領域を切り捨てて領域がなくなるまで
  
  N = int(input())
  a = [0] + list(map(int, input().split()))
  
  l = 1
  r = N
  
  ans = []
  while l < r:
      # 正で一番大きいところ取得
      inde = l
      maxm = a[l]
      for i in range(l, r + 1, 1):
          if a[i] > maxm:
              inde = i
              maxm = a[i]
  
      # 負で一番大きいところ取得
      inde_hu = l
      minim = a[l]
      for i in range(l, r + 1, 1):
          if a[i] <= minim:
              inde_hu = i
              minim = a[i]
  
      if abs(maxm) >= abs(minim):
          tmp = inde
      else:
          tmp = inde_hu
  
      if a[tmp] > 0:
          for i in range(tmp, r, 1):
              ans.append([i, i + 1])
              ans.append([i, i + 1])
          r = tmp - 1
      else:
          for i in range(tmp, l, -1):
              ans.append([i, i - 1])
              ans.append([i, i - 1])
          l = tmp + 1
  
  print(len(ans))
  for i in range(len(ans)):
      print(ans[i][0], ans[i][1])
  
problem_description: Statement
  
  Snuke has an integer sequence, a, of length N. The i-th element of a
  (1-indexed) is a_{i}.
  
  He can perform the following operation any number of times:
  
    * Operation: Choose integers x and y between 1 and N (inclusive), and add a_x to a_y.
  
  He would like to perform this operation between 0 and 2N times (inclusive) so
  that a satisfies the condition below. Show one such sequence of operations. It
  can be proved that such a sequence of operations always exists under the
  constraints in this problem.
  
    * Condition: a_1 \leq a_2 \leq ... \leq a_{N}
samples: [{"input": "3\n    -2 5 -1", "output": "2\n    2 3\n    3 3\n    \n\n  * After the first operation, a = (-2,5,4).\n  * After the second operation, a = (-2,5,8), and the condition is now satisfied.\n\n* * *"}, {"input": "2\n    -1 -3", "output": "1\n    2 1\n    \n\n  * After the first operation, a = (-4,-3) and the condition is now satisfied.\n\n* * *"}, {"input": "5\n    0 0 0 0 0", "output": "0\n    \n\n  * The condition is satisfied already in the beginning."}]