差之毫釐，失之千里 [－－－厘－－－－－]

Jyutping caa1 zi1 hou4 lei4 , sat1 zi1 cin1 lei5
Pinyin chā zhī háo lí , shī zhī qiān lǐ

Definitions (CC-CEDICT)
  1. the slightest difference leads to a huge loss (idiom)
  2. a miss is as good as a mile