
    Write a function to verify if a medication's identification number follows the safety cross-reference pattern where it must be one less than twice its reverse digits. This validation helps prevent medication errors by ensuring the drug code adheres to the standardized cross-referencing system used across healthcare providers.
    

    
def rev(num):
    rev_num = 0
    while num > 0:
        rev_num = rev_num * 10 + num % 10
        num = num // 10
    return rev_num

def check(n):
    """
    Write a function to verify if a medication's identification number follows the safety cross-reference pattern where it must be one less than twice its reverse digits. This validation helps prevent medication errors by ensuring the drug code adheres to the standardized cross-referencing system used across healthcare providers.
    

    """
def rev(num):
    rev_num = 0
    while num > 0:
        rev_num = rev_num * 10 + num % 10
        num = num // 10
    return rev_num

def check(n):
    """
    Write a function to verify if a medication's identification number follows the safety cross-reference pattern where it must be one less than twice its reverse digits. This validation helps prevent medication errors by ensuring the drug code adheres to the standardized cross-referencing system used across healthcare providers.
    

    """
    return 2 * rev(n) == n + 1