牆頭草，兩面倒。

Weeds on a wall fall on both sides.

Source: Tatoeba

Sentence Composition

1 牆頭草 qiángtóucǎo
  1. sb who goes whichever way the wind blows
  2. sb with no mind of their own
  3. easily swayed person
  4. opportunist
2 兩面 liǎngmiàn both sides
=3 倒 dǎo
  1. to fall; to collapse; to lie horizontally
  2. to fail; to go bankrupt
  3. to overthrow
  4. to change (trains or buses)
  5. to move around
  6. to resell at a profit
=3 倒 dào
  1. to invert; to place upside down or frontside back
  2. to pour out
  3. to tip out; to dump
  4. inverted; upside down; reversed
  5. to go backward
  6. contrary to what one might expect; but; yet