n,m,x = map(int,input().split())
ab = []
for _ in range(n):
    a,b = map(int,input().split())
    ab.append([a,b])
ab.sort(key = lambda x:(-x[0],x[1]))
ab_ans = [] 
vis = [0] * n
from collections import defaultdict
d = defaultdict(int)
rui = 0
syu = 0
j = 0
for i in range(n):
    a,b = ab[i]
    if vis[i] == 1:continue
    if d[b] == 0:
        ab_ans.append([a,b])
        syu += 1
        vis[j] = 1
        d[b] += 1
    else:
        j = max(i+1,j)
        while j <= n-1 :
            if d[ab[j][1]] == 0:
                if a + syu * x <= (syu + 1) * x + ab[j][0]:
#                     print(i,j,a + syu * x, (kari_syu + 1) * x + ab[j][0])
                    vis[j] = 1
                    ab_ans.append([ab[j][0],ab[j][1]])
                    d[ab[j][1]] += 1
                    syu += 1
                else:
                    break
            j += 1
        ab_ans.append([a,b])
        vis[i] = 1
        d[b] += 1
        
k = int(input())
c = list(map(int,input().split()))
rui = [0] * n
rui_syu = [0] * n
d = defaultdict(int)
syu = 0
for i in range(n):
    a,b = ab_ans[i]
    if d[b] == 0:
        syu += 1
        rui_syu[i] += syu * x
        d[b] += 1
    else :
        rui_syu[i] += rui_syu[i-1]
    rui[i] = a
for i in range(1,n):
    rui[i] += rui[i-1]
ans = 0
for i in range(k):
    if c[i] == 0:continue
    ans += rui[c[i]-1] + rui_syu[c[i]-1]
print(ans)