output_description: Print the number of sand in the upper bulb after t second.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      X t
attempt: import functools
  
  import os
  
  INF = float("inf")
  
  
  def inp():
      return int(input())
  
  
  def inpf():
      return float(input())
  
  
  def inps():
      return input()
  
  
  def inl():
      return list(map(int, input().split()))
  
  
  def inlf():
      return list(map(float, input().split()))
  
  
  def inls():
      return input().split()
  
  
  def inpm(line):
      return [inp() for _ in range(line)]
  
  
  def inpfm(line):
      return [inpf() for _ in range(line)]
  
  
  def inpsm(line):
      return [inps() for _ in range(line)]
  
  
  def inlm(line):
      return [inl() for _ in range(line)]
  
  
  def inlfm(line):
      return [inlf() for _ in range(line)]
  
  
  def inlsm(line):
      return [inls() for _ in range(line)]
  
  
  def debug(fn):
      if not os.getenv("LOCAL"):
          return fn
  
      @functools.wraps(fn)
      def wrapper(*args, **kwargs):
          print(
              "DEBUG: {}({}) -> ".format(
                  fn.__name__,
                  ", ".join(
                      list(map(str, args))
                      + ["{}={}".format(k, str(v)) for k, v in kwargs.items()]
                  ),
              ),
              end="",
          )
          ret = fn(*args, **kwargs)
          print(ret)
          return ret
  
      return wrapper
  
  
  x, y = inl()
  print(x - y)
  
problem_description: Statement
  
  We have a sandglass that runs for X seconds. The sand drops from the upper
  bulb at a rate of 1 gram per second. That is, the upper bulb initially
  contains X grams of sand.
  
  How many grams of sand will the upper bulb contains after t seconds?
samples: [{"input": "100 17", "output": "83\n    \n\n17 out of the initial 100 grams of sand will be consumed, resulting in 83\ngrams.\n\n* * *"}, {"input": "48 58", "output": "0\n    \n\nAll 48 grams of sand will be gone, resulting in 0 grams.\n\n* * *"}, {"input": "1000000000 1000000000", "output": "0"}]