storage capacity

def storage_capacity(box_heights, shelf_heights):
    box_count = 0
    last_filled_shelf = len(shelf_heights)
    result = [-1]*len(shelf_heights)
    for box_height in box_heights:
        shelf_idx = 0
        while box_height<=shelf_heights[shelf_idx] and shelf_idx<last_filled_shelf-1:
            shelf_idx+=1
            
        result[shelf_idx]=box_height
        last_filled_shelf=shelf_idx-1
        box_count+=1
        if last_filled_shelf==-1:
            return box_count
    return box_count 
    
shelf_heights = [3, 4, 2, 3]   
box_heights = [2, 3, 3, 4, 5]
print(storage_capacity(box_heights, shelf_heights)) ## (box2,box1,empty,box0)
box_heights = [3, 3, 3]
print(storage_capacity(box_heights, shelf_heights))
box_heights = [8, 3, 3]
print(storage_capacity(box_heights, shelf_heights))