General ACCAIs it advisable to take P1 &P3 together within one month on Dec 17 exam

I'm currently working full time,5 days a week,I've attend tuition class for both papers,but I'm quite busy past few months and didn't make any revision. Now I'm facing dilemma whether to take only P1 on Dec 17,or take both P1 and P3.(I wish to clear Asap). But now only left one month,I will try my best to put all my effort. Just wonder,is it too risky to take two professional papers. I'm just cleared my F papers. New to P Papers. Any advise. Thanks.