Noun, Suru verb, Intransitive verb
putting the cart before the horse; mistaking the means for the end; getting one's priorities backwards
Yojijukugo (four character compound)
あなたの言っていることは本末転倒だと思わないかい？Don't you think you're putting the cart before the horse?
Also written 本末顛倒【ほんまつてんとう】、本末顚倒【ほんまつてんとう】