[SetUp "1"]
[FEN "3r4/p4k2/Pp6/1Bpr1pBp/2N4P/2Pn1R2/KP2b3/8 w - - 0 1"]

1.Re3 f4 ( 1...Bf1 2.Re7+ Kg6 3.Rxa7 ) 2.Rxe2 ( 2.Re7+ Kg6 3.Rxa7
Rxg5 4.hxg5 f3 ) Nc1+ *