It is the rule in war, if ten times the enemy's strength, surround them; if five times, attack them; if double, be able to divide them; if equal, engage them; if fewer, defend against them; if weaker, be able to avoid them.
故用兵之法，十則圍之，五則攻之，倍則分之， 敵則能戰之，少則能守之，不若則能避之。
Original text (Chinese)