Just pop into any camping shop and buy a three or four fold mat, I think its called a Multimat or similar. Should cost you less than a fiver. I always carry one with me, worth its weight in gold! Multipurpose too, good for standing on with bare feet to wiggle my toes after a hard days hike, to rest my wet boots on in my tent overnight and even to stand on when I have to use a public shower, so many uses including to sit on as well.