Basic regex tasks. Write a function that takes in a numeric code of any length. The function should check if the code begins with 1, 2, or 3 and return `true` if so. Return `false` otherwise. 
You can assume the input will always be a number.
validate_code=lambda n:str(n).startswith(tuple('123'))
validate_code=lambda n:str(n).startswith(tuple('123'))