百里 ひゃくりを行 ゆく者 ものは九十 くじゅうを半 なかばとす

hyakurio yuku monowa kujūo nakabato su

1. don't count your chickens before they're hatched; there's many a slip 'twixt the cup and the lip; consider a journey of 100 ri to be halfway completed at 90 — literal