1980s war film: Front and Back Gate?

Hello all,
I visited the Soviet Union as a college student in May 1982 and saw a war film in Leningrad that, since I didn't speak Russian, didn't understand. Later in the trip I saw the same film advertised on this billboard in central Moscow. I can understand the title as "Front and" something. Can anyone make out the rest of the title? I'd love to see if this film is available now but I can't locate it.

It's called The Front Behind Enemy Lines.

Part 1: http://www.youtube.com/watch?v=FY0fDSPW-fA

Part 2: http://www.youtube.com/watch?v=V2o5XnFjS-4

Thank you very much!!!