output_description: Print the earliest possible time for the kangaroo to reach coordinate X.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      X
attempt: import sys
  
  [n, k] = [int(x) for x in input().strip().split()]
  a = [int(x) for x in input().strip().split()]
  
  a.sort()
  
  if sum(a) < k:
      print(n)
      sys.exit()
  
  s = 0
  for i in range(len(a)):
      s += a[i]
      if s >= k:
          break
  
  aa = [x for x in a if x < a[i]]
  bb = [x for x in a if x < k]
  
  cc = []
  for i in range(len(aa)):
      c = bb[:i] + bb[i + 1 :]
      t = k - bb[i]
      c.reverse()
      # print(c)
      flg = 0
      j = 0
      s = 0
      f = [0 for x in range(len(c))]
      while True:
          f[j] = 1
          # print(c)
          # print(f)
          s += c[j]
          if s >= t and s < k:
              flg = 1
              # print(c)
              # print(f)
              break
          if s >= k:
              f[j] = 0
              s -= c[j]
          j += 1
          if j == len(c):
              ii = -1
              for jj in range(len(c) - 1):
                  if f[jj] == 1:
                      ii = jj
              if ii == -1:
                  break
              else:
                  for l in range(ii, len(c)):
                      f[l] = 0
              j = ii + 1
              s = sum([c[l] * f[l] for l in range(len(c))])
      if flg == 0:
          cc.append(bb[i])
  # print(cc)
  print(len(cc))
  
problem_description: Statement
  
  There is a kangaroo at coordinate 0 on an infinite number line that runs from
  left to right, at time 0. During the period between time i-1 and time i, the
  kangaroo can either stay at his position, or perform a jump of length exactly
  i to the left or to the right. That is, if his coordinate at time i-1 is x, he
  can be at coordinate x-i, x or x+i at time i. The kangaroo's nest is at
  coordinate X, and he wants to travel to coordinate X as fast as possible. Find
  the earliest possible time to reach coordinate X.
samples: [{"input": "6", "output": "3\n    \n\nThe kangaroo can reach his nest at time 3 by jumping to the right three times,\nwhich is the earliest possible time.\n\n* * *"}, {"input": "2", "output": "2\n    \n\nHe can reach his nest at time 2 by staying at his position during the first\nsecond, and jumping to the right at the next second.\n\n* * *"}, {"input": "11", "output": "5"}]