Slices & loops

A slice i32[] is a fat pointer — a pointer plus a length. You can iterate its elements directly with a for-in loop:

for x in xs {
    total = total + x
}

The starter gives you sum(i32[] xs) that should add up every element, and a main that calls it with [1, 2, 3, 4, 5].

Your task: complete sum using a for-in loop that accumulates into total. When correct, main returns 15.