일석이조
一石二鳥 · one stone, two birds
Getting two benefits from one action.
When to useA plan that solves two problems at once.
Examples
걸어서 출근하면 운동도 되고 돈도 아끼니 일석이조야.
Walking to work saves money and counts as exercise — two birds, one stone.
Korean life dictionary
22 short guides to words and manners