C++

Number of solutions: 1 Solution 1: ab@bb@bbbccc@c @bbddbb@b@cccc aa@d@bbbbde@cc @adddd@d@dgecc aaa@fddddd@e@c a@hff@f@gggeee ihh@hfjjj@g@ee i@hih@kjjeeee@ iii@hkkj@j@len @iiiik@jjjll@n mm@m@kkkkj@lnn mmmmmk@k@jjjn@ m@mm@mkkknj@nn mmmmmmm@k@nnn@