output_description: Print the maximum possible number of honest persons among the N people.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      A_1
      x_{11} y_{11}
      x_{12} y_{12}
      :
      x_{1A_1} y_{1A_1}
      A_2
      x_{21} y_{21}
      x_{22} y_{22}
      :
      x_{2A_2} y_{2A_2}
      :
      A_N
      x_{N1} y_{N1}
      x_{N2} y_{N2}
      :
      x_{NA_N} y_{NA_N}
attempt: def max_honest(n_ppl, testimonies):
      formating_str = "{0:0" + str(n_ppl) + "b}"
      max = 0
      for i in range(1, 2**n_ppl + 1):
          current_val = formating_str.format(2**n_ppl - i)
          potential = True
          valid_testemonies = []
          for j in range(0, len(current_val)):
              if current_val[j] == "1":
                  for k in range(0, len(testimonies[j])):
                      valid_testemonies.append(testimonies[j][k])
          for j in range(0, len(valid_testemonies)):
              if str(valid_testemonies[j][1]) != current_val[valid_testemonies[j][0] - 1]:
                  potential = False
                  break
          if potential:
              if current_val.count("1") > max:
                  max = current_val.count("1")
      return max
  
  
  testimonies = []
  n_ppl = int(input())
  
  for i in range(0, n_ppl):
      tests = []
      n_tests = int(input())
      for j in range(0, n_tests):
          test = input().split(" ")
          test = (int(test[0]), int(test[1]))
          tests.append(test)
      testimonies.append(tests)
  
  print("")
  print(max_honest(n_ppl, testimonies))
  input("Press enter")
  
problem_description: Statement
  
  There are N people numbered 1 to N. Each of them is either an _honest_ person
  whose testimonies are always correct or an _unkind_ person whose testimonies
  may be correct or not.
  
  Person i gives A_i testimonies. The j-th testimony by Person i is represented
  by two integers x_{ij} and y_{ij}. If y_{ij} = 1, the testimony says Person
  x_{ij} is honest; if y_{ij} = 0, it says Person x_{ij} is unkind.
  
  How many honest persons can be among those N people at most?
samples: [{"input": "3\n    1\n    2 1\n    1\n    1 1\n    1\n    2 0", "output": "2\n    \n\nIf Person 1 and Person 2 are honest and Person 3 is unkind, we have two honest\npersons without inconsistencies, which is the maximum possible number of\nhonest persons.\n\n* * *"}, {"input": "3\n    2\n    2 1\n    3 0\n    2\n    3 1\n    1 0\n    2\n    1 1\n    2 0", "output": "0\n    \n\nAssuming that one or more of them are honest immediately leads to a\ncontradiction.\n\n* * *"}, {"input": "2\n    1\n    2 0\n    1\n    1 0", "output": "1"}]