Out of practice

[kali]

I've just entered to piano street and hope to find interesting and helpful advise. This is the thing, i am a 20yr old mexican girl, and i started playing at five but stopped two years ago when entered university to study mechatronics. Now, my school is inviting me to a concert kind-of-contest-thing and i have no repertoire ready. I have ten months to the concert and i've just "met" mendelssohn's phantasie op.28 and im dying to start with it but im afraid i wont have it ready for the concert. The last pieces i played were a bunch of preludes and things and the pathethique sonata. So, i would like to know how long it took those who have played this piece to master it The three movements of course, im missing the last two, shall i play them?

Sorry for grammar and spellings..

[happyface94]

You have 10 month. You can prepare newer things. 10 month is the usual time for me to prepare a 50 minute program.