!-n
The command n lines back, counting from the end.
Instead of the absolute line number, the distance: !-2 is the command before last, !-3 the one before that. !-1 and !! are the same relic under two names.
It's the right designator for alternating between two commands — configure, build, configure again — without counting lines in history.
$ ./configurar.sh
$ ./compilar.sh
$ !-2
./configurar.sh