单丝不成线，独木不成林
dān​sī​bù​chéng​xiàn, dú​mù​bù​chéng​lín

cooperation

单丝不成线，独木不成林 (單絲不成線，獨木不成林) dān​sī​bù​chéng​xiàn, dú​mù​bù​chéng​lín
cooperation
one strand does not make a thread, one tree does not make a forest; a proverb meaning that an individual cannot achieve significant results without collective effort

Sources
Definitions
CC-CEDICT