output_description: If it is possible to give cookies so that each of the three goats can have the
  same number of cookies, print `Possible`; otherwise, print `Impossible`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B
attempt: # coding=UTF-8
  
  N = int(input())
  moti = list(range(0, N, 1))
  
  # initalize
  for idx in range(0, N, 1):
      moti[idx] = []
  
  # input
  for idx in range(0, N - 1, 1):
      mozir = input()
      hyo = mozir.split(" ")
      a = int(hyo[0]) - 1
      b = int(hyo[1]) - 1
  
      moti[a].append(b)
      moti[b].append(a)
  
  # path 0 to N-1
  # width serach
  belong = list(range(0, N, 1))
  for idx in range(0, N, 1):
      belong[idx] = None
  
  belong[0] = "F"
  belong[N - 1] = "S"
  
  fennec_watch = [0]
  sunuke_watch = [N - 1]
  fennec_haven = 1
  sunuke_haven = 1
  fennec_zou = 1  # for breaking cond
  sunuke_zou = 1  # also
  Teban = "F"
  while True:
      if Teban == "F":
          fennec_next = []
          for mono in fennec_watch:
              kouho = moti[mono]
              for butu in kouho:
                  if belong[butu] == None:
                      fennec_next.append(butu)
                      belong[butu] = "F"
  
          fennec_watch = fennec_next
          fennec_zou = len(fennec_next)
          fennec_haven = fennec_haven + fennec_zou
      else:
          sunuke_next = []
          for mono in sunuke_watch:
              kouho = moti[mono]
              for butu in kouho:
                  if belong[butu] == None:
                      sunuke_next.append(butu)
                      belong[butu] = "S"
  
          sunuke_watch = sunuke_next
          sunuke_zou = len(sunuke_next)
          sunuke_haven = sunuke_haven + sunuke_zou
  
      if fennec_zou == 0 and sunuke_zou == 0:
          break
      Teban = "F" if Teban == "S" else "S"
  
  # when fennec_haven==sunuke_haven==k
  # k+1 th turn fennec 33-4
  if fennec_haven > sunuke_haven:
      print("Fennec")
  else:
      print("Snuke")
  
problem_description: Statement
  
  Snuke is giving cookies to his three goats.
  
  He has two cookie tins. One contains A cookies, and the other contains B
  cookies. He can thus give A cookies, B cookies or A+B cookies to his goats (he
  cannot open the tins).
  
  Your task is to determine whether Snuke can give cookies to his three goats so
  that each of them can have the same number of cookies.
samples: [{"input": "4 5", "output": "Possible\n    \n\nIf Snuke gives nine cookies, each of the three goats can have three cookies.\n\n* * *"}, {"input": "1 1", "output": "Impossible\n    \n\nSince there are only two cookies, the three goats cannot have the same number\nof cookies no matter what Snuke gives to them."}]