def sumMerge(dict1, dict2):
    """
    Adds two dictionaries together, and merges into the first, dict1.
    Returns first dict.
    """
    for key in dict2:
        dict1[key] = list(map(lambda a, b: a + b, dict1.get(key, [0, 0, 0, 
            0]), dict2[key]))
    return dict1
