In response to the American Boeing X-32/Joint Strike Fighter (F-35) projects, Russia began the "LFI" program, which would develop a fighter reminiscent of the X-32/F-35 with a single engine, without the capabilities of a true multirole aircraft. The LFI (Lyogkiy Frontovoy Istrebitel, Light Frontline Fighter) project was intended to develop a lightweight fighter with respectable air-to-ground capabilities. Yakovlev proposed the Yak-43, an upgraded Yakolev Yak-41 with a stealthier design and more powerful engines. After neglecting the MFI competition, Sukhoi decided to submit a design for the LFI called the S-37 (unrelated to the heavyweight forward-swept wing fighter). This S-37 resembled the Gripen in that it had canard foreplanes, a delta wing and one engine. Mikoyan entered the MiG 4.12. MiG could not afford to develop both the MFI and LFI, so their LFI entry was eventually withdrawn. Developed into Mikoyan LMFS.