text: def Tribonacci_Number(n):
      if n == 0 :
          return 0
      elif n == 1 or n == 2 :
          return 1
      else :
          return (Tribonacci_Number(n-1) + Tribonacci_Number(n-2) + Tribonacci_Number(n-3))
  
  N = input("Enter n for find nth Tribonacci Number : ")
  
  print(N,"th Tribonacci Number is : ",Tribonacci_Number(int(N)))