from heapq import *
N,M,X = map(int,input().split())
AB = [list(map(int,input().split())) for _ in range(N)]
K = int(input())
C = list(map(int,input().split()))
J = [[] for _ in range(M)]
Y = [0] * N
Q1 = []
Q2 = []
solved = set()

for a,b in AB:
    b -= 1
    J[b].append(a)
for c in C:
    if c > 0:
        Y[c - 1] += 1

for i in range(M):
    if J[i]:
        J[i].sort()
        x = J[i].pop()
        heappush(Q1,(-x,i))

ans = 0
tmp = 0
for i in range(N):
    if Q2:
        if Q1:
            if Q1[0][0] - M < Q2[0][0]:
                x, jn = heappop(Q1)
                tmp += -x + X
            else:
                x, jn = heappop(Q2)
                tmp += -x
        else:
            x, jn = heappop(Q2)
            tmp += -x
    else:
        if Q1:
            x, jn = heappop(Q1)
            tmp += -x + X
    if J[jn]:
        heappush(Q2,(-J[jn].pop(),jn))
    ans += tmp * Y[i]
    #print(i,tmp,Y[i],ans)
print(ans)