Aditya started from his tuition point, walks 17 m towards the north to reach the bakery then takes a right turn and walks 12 m to reach the bookstall after that he takes right turn again, walks 27 m and stops at his apartment. Roshan also starts from the same tuition point, walks 18 m towards the south to reach the library, then takes a left turn and walks 18 m before stopping at his apartment. What is the shortest distance between Roshan’s apartment and Aditya’s apartment?