
    In a bank's fraud detection system, write a function that activates the next highest-priority security verification that hasn't been performed yet, given a binary status flag where each bit represents a completed (1) or pending (0) security check. The function should identify and set the leftmost unset bit in the status flag, effectively marking the highest-priority pending security check as completed.
    

    
def set_left_most_unset_bit(n):
    """
    In a bank's fraud detection system, write a function that activates the next highest-priority security verification that hasn't been performed yet, given a binary status flag where each bit represents a completed (1) or pending (0) security check. The function should identify and set the leftmost unset bit in the status flag, effectively marking the highest-priority pending security check as completed.
    

    """
def set_left_most_unset_bit(n):
    """
    In a bank's fraud detection system, write a function that activates the next highest-priority security verification that hasn't been performed yet, given a binary status flag where each bit represents a completed (1) or pending (0) security check. The function should identify and set the leftmost unset bit in the status flag, effectively marking the highest-priority pending security check as completed.
    

    """
    if not n & n + 1:
        return n
    (pos, temp, count) = (0, n, 0)
    while temp:
        if not temp & 1:
            pos = count
        count += 1
        temp >>= 1
    return n | 1 << pos