mod = 1000000007
eps = 10**-9


def main():
    import sys
    from heapq import heappush, heappop
    input = sys.stdin.buffer.readline

    N, M, X = map(int, input().split())
    AB = []
    best = [-1] * (M+1)
    best_idx = [-1] * (M+1)
    for i in range(N):
        a, b = map(int, input().split())
        if a > best[b]:
            best[b] = a
            best_idx[b] = i
        AB.append((a, b))
    pq_unseen = [10 ** 15]
    pq_seen = [10 ** 15]
    used = set()
    for j in range(1, M+1):
        if best_idx[j] != -1:
            heappush(pq_unseen, -best[j])
            used.add(best_idx[j])
    for i in range(N):
        a, b = AB[i]
        if i not in used:
            heappush(pq_seen, -a)
    D = []
    for _ in range(N):
        p = -pq_seen[0]
        q = -pq_unseen[0] + X
        if p > q:
            D.append(p)
            heappop(pq_seen)
        else:
            D.append(q)
            heappop(pq_unseen)

    cs = [0] * (N+1)
    for i in range(N):
        cs[i+1] = cs[i] + D[i]
    K = int(input())
    C = list(map(int, input().split()))
    ans = 0
    for c in C:
        ans += cs[c]
    print(ans)


if __name__ == '__main__':
    main()