as long as one does; if only one does; all one has to do is
Attaches to the 連用形 (masu-stem) of a verb or to a noun + を/が to express that doing or having that thing is sufficient for a desired result. Often used in conditional or hypothetical contexts.
As long as you make an effort, your dreams will come true.
All you have to do is press this button, and the machine will start.