#include <stdio.h>

typedef struct {
	long long key;
	int id;
} data;

typedef struct {
	data obj[200001];
	int size;
} max_heap;

void push(max_heap* h, data x)
{
	int i = ++(h->size), j = i >> 1;
	data tmp;
	h->obj[i] = x;
	while (j > 0) {
		if (h->obj[i].key > h->obj[j].key) {
			tmp = h->obj[j];
			h->obj[j] = h->obj[i];
			h->obj[i] = tmp;
			i = j;
			j >>= 1;
		} else break;
	}
}

data pop(max_heap* h)
{
	int i = 1, j = 2;
	data output = h->obj[1], tmp;
	h->obj[1] = h->obj[(h->size)--];
	while (j <= h->size) {
		if (j < h->size && h->obj[j^1].key > h->obj[j].key) j ^= 1;
		if (h->obj[j].key > h->obj[i].key) {
			tmp = h->obj[j];
			h->obj[j] = h->obj[i];
			h->obj[i] = tmp;
			i = j;
			j <<= 1;
		} else break;
	}
	return output;
}

int main()
{
	int i, N, M, X, A, B;
	data d;
	max_heap h;
	h.size = 0;
	scanf("%d %d %d", &N, &M, &X);
	for (i = 1; i <= N; i++) {
		scanf("%d %d", &A, &B);
		d.key = A + X;
		d.id = B;
		push(&h, d);
	}
	
	int K, C, num[200001] = {};
	scanf("%d", &K);
	for (i = 1; i <= K; i++) {
		scanf("%d", &C);
		num[C]++;
	}
	
	int flag[200001] = {};
	long long ans = 0, tmp = 0;
	for (i = 1; i <= N; i++) {
		do {
			d = pop(&h);
			if (d.id > 0) {
				if (flag[d.id] == 0) {
					flag[d.id] = 1;
					tmp += d.key;
					break;
				} else {
					d.key -= X;
					d.id *= -1;
					push(&h, d);
				}
			} else {
				tmp += d.key;
				break;
			}
		} while (1);
		ans += tmp * num[i];
	}
	printf("%lld\n", ans);
	fflush(stdout);
	return 0;
}