Count Good Selections

Gustavo Fring is the owner of a leading food chain called Los Pollos Hermanos in Albuquerque, New Mexico. Given $N, M, S$. The restaurant has $N$ food items and the cost of all the items is denoted by an array $C$. He has to select some food items from the available $N$ items and he needs to pack them together. The selected items are good if it is possible to separate the costs of the selected it