A mass M is broken into two parts, m & (M-m). How is m related to M so that the gravitational force between two parts is maximum?

A mass M is broken in to two parts m and (M-m).How is m related to M so that the gravtational force between two parts is maximum?

A mass M is broken into two parts of masses m_1 and m_2 . How are m_1 and m_2 related so that force of gravitational attraction between the two parts is maximum ?