TRIP

$Chef$ wants to buy chocolates from Canteen for a $trip$. Chef has $S$ Rupees in his pocket. He wants to use $all$ of them. The canteen has $N$ chocolates of costs $C_1, C_2, ..., C_N$. A $non-empty$ subset $P$ of $\{1, 2, 3, ..., N\}$ is $good$ if, - $∑ C_k = S, k∈P$ - $P$ consists of $all$ $k$, k∈\{1, 2, ..., N\} such that $C_k\%5 == 0$. You need find the $number$ of $g