expression
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.
努力さえすれば、夢は叶う。
As long as you make an effort, your dreams will come true.
このボタンを押しさえすれば、機械が動き出す。
All you have to do is press this button, and the machine will start.