import itertools


class Task:
    def run(self):
        N, M, X = map(int, input().split())

        questions = [list(map(int, input().split())) for _ in range(N)]

        K = int(input())
        C = list(map(int, input().split()))

        max_satisfy_score = 0
        for ptn in itertools.permutations(questions):
            satisfy_score_sum = 0
            for c in C:
                answered = ptn[:c]
                quality_sum = sum([q for q, g in answered])
                number_of_genre = len(set([g for q, g in answered]))
                satisfy_score = quality_sum + X * number_of_genre
                satisfy_score_sum += satisfy_score

            if max_satisfy_score < satisfy_score_sum:
                max_satisfy_score = satisfy_score_sum

        print(max_satisfy_score)


if __name__ == "__main__":
    task = Task()
    task.run()