Theory of relativity farmer question help needed fast....!!!?

understanding of the farmer's paradox: a farmer has a ladder that is too long to fit in his barn horizontally. He knows some relativity and thinks moving objects shrinks in dimension. He runs near the speed of light so that his ladder shrinks down to fit in his barn. Someone will slam the door shut once the back of the ladder pes the door (yeah). On another thought, he considers the barn moving toward him and should shrink in dimension, which makes it harder to accommodate his ladder. Is his first thought right or second thought right? Explain.