hello Codeforces community, i participated in the "Red de Programacion Competitiva" activity #3 :

https://acm.javeriana.edu.co/maratones/2016/03/

and i would like you to help me in, how can I solve the "Problem B. Tobby Bones":

here is the link of the problems:

https://acm.javeriana.edu.co/maratones/2016/03/filedownload.php?oid=-1&filename=OFlRXXMRQmOnKS1eKONXXl6aKpqbQFcFtUPEmaLLNHkBn%2FcNI%2BgOFZt3gP%2FcdvnyM9fYowpCHgCOC9ijoWEi5LGlnjHDYwqH2XmU4zD4TycQaNrwqFkF6a6CrhGOORUYk64tYtUcim6LBgN2Ju7IV16fZoTNEN45xPJpNYS5mJFhvdmgSoSAuR07wqVtBNWS%2BNWgXyseW0jjEVWd3Si3wA%3D%3D&check=89a3e84eff6c83b371dba559fa475b58f51ff7da3589127492ff6ad7ddb86cbf

Thanks and sorry for my english