def bubbleSort(lis): #This function sorts a list with "bubble sort".
    for i in range(len(lis)):
        for j in range(len(lis)-1-i):#"-i" becuase after the iteration it is already sorted, so we don't have to check it.
            if lis[j].num_ships() < lis[j+1].num_ships(): #Check which number is bigger.
                lis[j], lis[j+1] = lis[j+1], lis[j] #Swap if needed.
    return lis #returns the list sorted