先決 せんけつ
senketsu

Noun
Suru Verb

1. deciding first; settling (a matter) first; first priority

Transitive
きみ煙草 たばこ うのをやめるのが先決 せんけつだ。
kimiwa tabakō sū nō yameru noga senketsuda.
First, you have to stop smoking.