def main():
    N, M, X = map(int, input().split(' '))
    ABs = [tuple(map(int, input().split(' '))) for _ in range(N)]
    K = int(input())
    Cs = list(map(int, input().split(' ')))

    genre_qualities = dict()
    for AB in ABs:
        if AB[1] in genre_qualities:
            genre_qualities[AB[1]] += [AB[0]]
        else:
            genre_qualities[AB[1]] = [AB[0]]

    values = []
    for k in genre_qualities.keys():
        genre_qualities[k] = sorted(genre_qualities[k], reverse=True)
        genre_qualities[k][0] += X
        values += genre_qualities[k]

    maximized = sorted(values, reverse=True)
    satisfactions = [sum(maximized[:C]) for C in Cs]

    print(sum(satisfactions))

if __name__ == '__main__':
    main()