text: from __future__ import annotations
  from typing import Generic, TypeVar, Dict
  
  K = TypeVar('K')
  V = TypeVar('V')
  pair = TypeVar('Pair')
  
  
  class Pair(Generic[K, V]):
  
      def __init__(self, first, second) -> None:
          self.first: K = first
          self.second: V = second
      
      def __str__(self) -> str:
          return f"first: {self.first}, second: {self.second}"
  
  
  class Node(Generic[pair]):
      pass
  
  class RedBlackTree():
      pass
  
  if __name__ == '__main__':
      p = Pair[int, int](1, 3)
      print(p)
  