output_description: Print the string representing the type of the contest held this week.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: N, M = map(int, input().split())
  H = list(map(int, input().split()))
  tunagari = [[] for i in range(N)]
  for i in range(M):
      A, B = map(int, input().split())
      tunagari[A - 1] += [B - 1]
      tunagari[B - 1] += [A - 1]
  
  nums = [0 for i in range(N)]
  t = 0
  for i in range(N):
      tmpl = tunagari[i]
      mini = min(tmpl)
      if mini < i:
          nums[i] = nums[mini]
          continue
      nums[i] = t
      t += 1
  maxn = max(nums)
  groups = [[] for i in range(maxn + 1)]
  print(maxn + 1)
  for i in range(N):
      groups[nums[i]] += [i]
  ans = 0
  
  for i in range(maxn):
      tmpl = groups[i]
      tmpl2 = []
      for i in tmpl:
          tmpl2 += [H[i]]
      n = len(tmpl)
      if n == 1:
          ans += 1
      else:
          tmpl2.sort()
          if tmpl2[-1] != tmpl2[-2]:
              ans += 1
  
problem_description: Statement
  
  AtCoder Inc. holds a contest every Saturday.
  
  There are two types of contests called ABC and ARC, and just one of them is
  held at a time.
  
  The company holds these two types of contests alternately: an ARC follows an
  ABC and vice versa.
  
  Given a string S representing the type of the contest held last week, print
  the string representing the type of the contest held this week.
samples: [{"input": "ABC", "output": "ARC\n    \n\nThey held an ABC last week, so they will hold an ARC this week."}]