Stuck in my project:Fill the ship with products (max efficiency)

[hammerofdoom]

Hey guys, I will start my simple project but I still confuse about the main points.

Here basic story of my project: Imagine that one little ship has got one big store place.We also know exactly measurements of the this storage place.
For example:storage place dimensions length=50 meters, height=15meters, width=20meters

Users should add input values(x,y,z) of products in the storage.I will declare some variables like x(length), y(height), z(width) for product sizes.

And I want to fill the storage with maximum efficiency.So how should I start, and which type methods should I use and I need some advice ty guys

[Duthomhas]

This is a common CS problem called the Knapsack problem.
Read all about it here: https://en.wikipedia.org/wiki/Knapsack_problem