output_description: Print all days on which Takahashi is bound to work in ascending order, one per
  line.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N K C
      S
attempt: import sys
  
  sys.setrecursionlimit(100000000)
  
  
  def main():
      N, K, C = map(int, input().split())
      S = input()
  
      def forward(k):
          i = 0
          day = 0
          days = [-1] * k
          l = len(S)
          while day < k and i < l:
              while S[i] == "x":
                  i += 1
                  if i >= l:
                      return None
              days[day] = i
              day += 1
              i += 1 + C
          if day < k:
              return None
          return days
  
      def backward(k):
          day = k
          days = [-1] * k
          l = len(S)
          i = l - 1
          while day > 0 and i >= 0:
              while S[i] == "x":
                  i -= 1
                  if i < 0:
                      return None
              day -= 1
              days[day] = i
              i -= 1 + C
          if day > 0:
              return None
          return days
  
      left = forward(K)
      if left is None:
          return
  
      right = backward(K)
      for i, j in zip(left, right):
          if i == j:
              print(i + 1)
  
  
  main()
  
problem_description: Statement
  
  Takahashi has decided to work on K days of his choice from the N days starting
  with tomorrow.
  
  You are given an integer C and a string S. Takahashi will choose his workdays
  as follows:
  
    * After working for a day, he will refrain from working on the subsequent C days.
    * If the i-th character of S is `x`, he will not work on Day i, where Day 1 is tomorrow, Day 2 is the day after tomorrow, and so on.
  
  Find all days on which Takahashi is bound to work.
samples: [{"input": "11 3 2\n    ooxxxoxxxoo", "output": "6\n    \n\nTakahashi is going to work on 3 days out of the 11 days. After working for a\nday, he will refrain from working on the subsequent 2 days.\n\nThere are four possible choices for his workdays: Day 1,6,10, Day 1,6,11, Day\n2,6,10, and Day 2,6,11.\n\nThus, he is bound to work on Day 6.\n\n* * *"}, {"input": "5 2 3\n    ooxoo", "output": "1\n    5\n    \n\nThere is only one possible choice for his workdays: Day 1,5.\n\n* * *"}, {"input": "5 1 0\n    ooooo", "output": "There may be no days on which he is bound to work.\n\n* * *"}, {"input": "16 4 3\n    ooxxoxoxxxoxoxxo", "output": "11\n    16"}]