Kautilya's Arthashastra 7.18.3

7.18.3

tac ced ubhayaṃ madhyamo 'nugṛhṇīyāt, vijigīṣur madhyamānulomaḥ syāt //

THE third and the fifth states from a madhyama king are states friendly to him; while the second, the fourth, and the sixth are unfriendly. If the madhyama king shows favour to both of these states, the conqueror should be friendly with him; if he does not favour them, the conqueror should be friendly with those states.