ㄉㄨˊㄇㄨˋdúmùㄅㄨˋㄔㄥˊchéngㄌㄧㄣˊlín

独木不成林
  1. 不了比喻個人力量薄弱不了大事 單絲不成線獨木不成林」。

a lone tree does not make a forest (idiom)​, one cannot accomplish much on one's own