
    In a bank's fraud detection system, develop a function that identifies and flags the most significant unchecked security verification in a transaction's security status bitmap. Given a binary security status where each bit represents a specific security check (0 for passed, 1 for failed), the function should mark the leftmost unmarked security verification as requiring additional review by setting its corresponding bit to 1.
    

    
def set_left_most_unset_bit(n):
    """
    In a bank's fraud detection system, develop a function that identifies and flags the most significant unchecked security verification in a transaction's security status bitmap. Given a binary security status where each bit represents a specific security check (0 for passed, 1 for failed), the function should mark the leftmost unmarked security verification as requiring additional review by setting its corresponding bit to 1.
    

    """
def set_left_most_unset_bit(n):
    """
    In a bank's fraud detection system, develop a function that identifies and flags the most significant unchecked security verification in a transaction's security status bitmap. Given a binary security status where each bit represents a specific security check (0 for passed, 1 for failed), the function should mark the leftmost unmarked security verification as requiring additional review by setting its corresponding bit to 1.
    

    """
    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