old_contents: import json
  import time
  
  def lambda_handler(event,context):
      number_1 = event['key1']
      number_2 = event['key2']
      return {"number" : abs(number_1 - number_2)}
new_contents: import json
  
  def lambda_handler(event, context):
      number_1 = int(event['key1'])
      number_2 = int(event['key2'])
      return {"number" : abs(number_1 - number_2)}
  
subject: Add int() function for casting from string to integer