def add_lists(list1, list2):
    """
    Add corresponding values of two lists together. The lists should have the same number of elements.
    
    Parameters
    ----------
    list1: list
        the first list to add
    list2: list
        the second list to add
        
    Return
    ----------
    output: list
        a new list containing the sum of the given lists
    """
    output = []
    for it1, it2 in zip(list1, list2):
        output.append(it1 + it2)
    return output