One for two
It's a Chinese idiom. Pinyin is y ī D ā Li ǎ ngy ò ng, which means one thing should be used in two ways.
Idiom usage
Your coat can be worn during the day and covered at night.
Idiom explanation
One set: 1. One group; one place; one piece. 2. Together. 3. Just like a lock. 4. A stack. dual use: 1. Combined use; use together. 2. Two usages or two uses.
One for two
work shame-facedly with one's enemies - miǎn yán shì dí