N,M,X = map(int,input().split())
    
import heapq
A = []
B = []

heapq.heapify(A)
heapq.heapify(B)

for i in range(N):
    a,b = map(int,input().split())
    heapq.heappush(B,(-a,b))
    
#print(B)
S = set()
ans = []
NOW = 0
while len(A) + len(B):
    
    while B and B[0][1] in S:
        b = heapq.heappop(B)
        heapq.heappush(A,b)
    #print(S,A,B)
    if len(B):
        b = B[0][0]
        if len(A):
            a = A[0][0]
            if -a < -b+X:
                b = heapq.heappop(B)
                ans.append(NOW + X -b[0])
                NOW = ans[-1]
                S.add(b[1])
            else:
                a = heapq.heappop(A)
                ans.append(NOW - a[0])
                NOW = ans[-1]
        else:
            b = heapq.heappop(B)
            ans.append(NOW + X -b[0])
            NOW = ans[-1]
            S.add(b[1])
    else:
        a = heapq.heappop(A)
        ans.append(NOW - a[0])
        NOW = ans[-1]
#print(ans)

ANS = 0
K = int(input())
C = list(map(int,input().split()))
for i in range(K):
    if C[i] > 0:
        ANS += ans[C[i]-1]
print(ANS)