Gosh that is a bit easy Kevin!!!
ANT-5/I-4 - (first aircraft Sukhoy designed)
ANT-5 was a prototype of I-4 sesquiplane single-seat fighter. I-4 differed from ANT-5 by redesigned (to decrease drag) engine howling, added rocket launchers on upper wing and increased tailfin. The lower wing was nothing more than an attachment for the wing struts; it was (almost) removed in the second series (I-4bis), used as a parasite fighter in Zveno experiments with TB-3 bomber. The I-4 was the first Soviet all metal fighter. One 480hp M-22. 369 were built.
A good page on it is http://www.ctrl-c.liu.se/misc/ram/i-4.html