
    Given a list of transaction amounts from multiple accounts within a monitoring period, write a function that calculates the sum of the highest and lowest transaction values to help identify potential fraudulent activity patterns. The function should analyze the transaction amounts and return a single value representing the combined total of the most extreme transactions.
    

    
def big_sum(nums):
    """
    Given a list of transaction amounts from multiple accounts within a monitoring period, write a function that calculates the sum of the highest and lowest transaction values to help identify potential fraudulent activity patterns. The function should analyze the transaction amounts and return a single value representing the combined total of the most extreme transactions.
    

    """
def big_sum(nums):
    """
    Given a list of transaction amounts from multiple accounts within a monitoring period, write a function that calculates the sum of the highest and lowest transaction values to help identify potential fraudulent activity patterns. The function should analyze the transaction amounts and return a single value representing the combined total of the most extreme transactions.
    

    """
    sum = max(nums) + min(nums)
    return sum