import sys
import io, os
input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

from heapq import heappop,heappush

K,N,M=map(int,input().split())

A=list(map(int,input().split()))
B=list(map(int,input().split()))

E=[[] for i in range(N)]

for i in range(M):
    u,v,d=map(int,input().split())
    u-=1
    v-=1
    E[u].append((v,d))
    E[v].append((u,d))

def dijkestra(fr):
    Q=[(0,fr)]

    DIS=[1<<61]*N
    DIS[fr]=0

    while Q:
        dis,now=heappop(Q)
        if DIS[now]!=dis:
            continue

        for to,cost in E[now]:
            if DIS[to]>dis+cost:
                DIS[to]=dis+cost
                heappush(Q,(DIS[to],to))

    return DIS
                
# 最小費用流

# まず、グラフ作り

V=N+N+2 # 頂点数

EDGE=[[] for i in range(V+1)]

def add_edge(u,v,k,c): # u→vに容量k, 費用cの辺を張る
    X=[v,c,k,[]]
    Y=X[3]=[u,-c,0,X]

    EDGE[u].append(X)
    EDGE[v].append(Y)

start=V-2
goal=V-1

C=[0]*N
for a in A:
    C[a-1]+=1

for i in range(N):
    if C[i]==0:
        continue
    add_edge(start,i,C[i],0)
    DIS=dijkestra(i)

    for j in range(N):
        add_edge(i,N+j,K,DIS[j])

for i in range(N):
    add_edge(N+i,goal,B[i],0)
    

#print(EDGE)

Flowed_edge=[[] for i in range(V)]
BACK=[-1]*(V)
P=[0]*(V) # ポテンシャル
LA=0 # 最終的な答え

for fl in range(K):
    ANS=[1<<62]*V
    Q=[start] # 一次元化している。(time<<20)+node
    ANS[start]=0

    while Q: # ここはダイクストラ
        x = heappop(Q)
        time = x>>20
        fr = x - (time<<20)
        if time > ANS[fr]:
            continue

        for to,cost,vol,f_edge in EDGE[fr]:        
            if vol>0 and ANS[to]>ANS[fr]+cost+P[fr]-P[to]:# ポテンシャルによりコストを調整        
                ANS[to]=ANS[fr]+cost+P[fr]-P[to]
                BACK[to]=fr
                Flowed_edge[to]=f_edge
                heappush(Q,((ANS[to])<<20)+to)

    LA+=ANS[goal]+P[goal]

    P=[P[i]+ANS[i] for i in range(V)] # ポテンシャルを調整
 
    NOW=goal
    while NOW!=start:
        f_edge=Flowed_edge[NOW]
        f_edge[3][2]-=1 # 流した分の容量を削る
        f_edge[2]+=1 # 逆向きに+1する

        NOW=BACK[NOW]

print(LA)