output_description: Print the N-th Lucas number.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
attempt: N = int(input())
  L = = [2, 1]
  for i in range(87):
      L.append(L[i]+L[i+1])
  print(L[N])
problem_description: Statement
  
  It is November 18 now in Japan. By the way, 11 and 18 are adjacent Lucas
  numbers.
  
  You are given an integer N. Find the N-th Lucas number.
  
  Here, the i-th Lucas number L_i is defined as follows:
  
    * L_0=2
    * L_1=1
    * L_i=L_{i-1}+L_{i-2} (i≥2)
samples: [{"input": "5", "output": "11\n    \n\n  * L_0=2\n  * L_1=1\n  * L_2=L_0+L_1=3\n  * L_3=L_1+L_2=4\n  * L_4=L_2+L_3=7\n  * L_5=L_3+L_4=11\n\nThus, the 5-th Lucas number is 11.\n\n* * *"}, {"input": "86", "output": "939587134549734843"}]