算了

let it be / let it pass / forget about it

to regard as / to figure / to calculate / to compute

(completed action marker) / (modal particle indicating change of state, situation now) / (modal particle intensifying preceding clause)

to finish / to achieve / variant of 瞭|了[liao3] / to understand clearly

(of eyes) bright / clear-sighted / to understand clearly

unofficial variant of 瞭[liao4]

if one is too calculating, it will be the cause of one's own undoing (famous line in "A Dream of Red Mansions" 紅樓夢|红楼梦[Hong2 lou2 Meng4])