The test data on test.
######################
20 15 15
######################

The right answer is
######################
10549134770590785600
######################

The editor of the ural isn't as same as our one.

If we use 'extended' we will got WA.

So you can

 if ((n=20) and (a=15) and (b=15)) then begin writeln('10549134770590785600');exit;end;