text: def get_fibonacci_last_digit_naive(n):
      if n <= 1:
          return n
  
      previous = 0
      current  = 1
  
      for _ in range(n - 1):
          previous, current = current%10, (previous + current)%10
  
      return current
  
  n = int(input())
  print(get_fibonacci_last_digit_naive(n))
  