# https://tjkendev.github.io/procon-library/python/min_cost_flow/primal-dual.html
# 最小費用流(minimum cost flow)
class MinCostFlow:
    def __init__(self, n):
        self.n = n
        self.G = [[] for i in range(n)]

    def addEdge(self, f, t, cap, cost):
        # [to, cap, cost, rev]
        self.G[f].append([t, cap, cost, len(self.G[t])])
        self.G[t].append([f, 0, -cost, len(self.G[f])-1])

    def minCostFlow(self, s, t, f):
        n = self.n
        G = self.G
        prevv = [0]*n; preve = [0]*n
        INF = 10**9+7

        res = 0
        while f:
            dist = [INF]*n
            dist[s] = 0
            update = 1
            while update:
                update = 0
                for v in range(n):
                    if dist[v] == INF:
                        continue
                    gv = G[v]
                    for i in range(len(gv)):
                        to, cap, cost, rev = gv[i]
                        if cap > 0 and dist[v] + cost < dist[to]:
                            dist[to] = dist[v] + cost
                            prevv[to] = v; preve[to] = i
                            update = 1
            if dist[t] == INF:
                return -1

            d = f; v = t
            while v != s:
                d = min(d, G[prevv[v]][preve[v]][1])
                v = prevv[v]
            f -= d
            res += d * dist[t]
            v = t
            while v != s:
                e = G[prevv[v]][preve[v]]
                e[1] -= d
                G[v][e[3]][1] += d
                v = prevv[v]
        return res

import sys
input = sys.stdin.readline
K, N, M = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
MCF = MinCostFlow(N+2)
INF = 10**16
for _ in range(M):
    u, v, d = map(int, input().split())
    MCF.addEdge(u, v, INF, d)
    MCF.addEdge(v, u, INF, d)
for a in A:
    MCF.addEdge(0, a, 1, 0)
for i in range(N):
    MCF.addEdge(i+1, N+1, B[i], 0)
ans = MCF.minCostFlow(0, N+1, K)
print(ans)