def get_int
  gets.chop.to_i
end

def get_ints
  gets.chop.split.map(&:to_i)
end

def get_double
  gets.chop.to_f
end

def get_str
  gets.chop
end

def get_strs
  gets.chop.split
end

def main
  nums = get_ints
  n = ([1, 2, 3] - nums)[0]
  puts n
end

if __FILE__ == $0
  main
end


