
    Given a binary representation of emergency room staff availability where 1 indicates a filled position and 0 indicates a vacancy, develop a function that identifies and fills the highest-priority unstaffed position (leftmost zero) in the hospital's staffing hierarchy. The function should update the staffing status by changing the leftmost zero to one, effectively assigning personnel to the most critical unstaffed role.
    

    
def set_left_most_unset_bit(n):
    """
    Given a binary representation of emergency room staff availability where 1 indicates a filled position and 0 indicates a vacancy, develop a function that identifies and fills the highest-priority unstaffed position (leftmost zero) in the hospital's staffing hierarchy. The function should update the staffing status by changing the leftmost zero to one, effectively assigning personnel to the most critical unstaffed role.
    

    """
def set_left_most_unset_bit(n):
    """
    Given a binary representation of emergency room staff availability where 1 indicates a filled position and 0 indicates a vacancy, develop a function that identifies and fills the highest-priority unstaffed position (leftmost zero) in the hospital's staffing hierarchy. The function should update the staffing status by changing the leftmost zero to one, effectively assigning personnel to the most critical unstaffed role.
    

    """
    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