text: 
  n= int(input())
  def Fibonacci(n): 
      if n<0: 
          print("Incorrect input") 
      
      elif n==1: 
          return 1
      
      elif n==2: 
          return 1
      else: 
          return Fibonacci(n-1)+Fibonacci(n-2) 
    
  
    
  print(Fibonacci(n)) 
  
  
  
  
  
  
  
  
  
  
  
  
  