#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); }
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } 

typedef long long ll;
// typedef vector<vector<int>> Graph;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define FOR(i,l,r) for (int i = l;i < (int)(r); i++)
#define rep(i,n) for (int i = 0;i < (int)(n); i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define my_sort(x) sort(x.begin(), x.end())
#define my_max(x) *max_element(all(x))
#define my_min(x) *min_element(all(x))
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = (1<<30) - 1;
const ll LINF = (1LL<<62) - 1;
const int MOD = 998244353;
const int MOD2 = 1e9+7;
const double PI = acos(-1);
vector<int> di = {1,0,-1,0};
vector<int> dj = {0,1,0,-1};

#ifdef LOCAL
#  include <debug_print.hpp>
#  define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define debug(...) (static_cast<void>(0))
#endif

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int K, N, M; cin >> K >> N >> M;
    vector<int> A(K);
    rep(i,K) cin >> A[i];
    vector<int> B(N);
    rep(i,N) cin >> B[i];
    using Edge = pair<ll, int>;
    vector<vector<Edge>> g(N);
    rep(i,M){
        int U, V; cin >> U >> V;
        ll D; cin >> D;
        g[U - 1].push_back(Edge{D, V - 1});
        g[V - 1].push_back(Edge{D, U - 1});
    }

    auto dijkstra = [&](int st){
        vector<ll> dist(N,LINF);
        dist[st] = 0ll;
        priority_queue<Edge,vector<Edge>,greater<Edge>> pq;
        pq.push(make_pair(dist[st], st));
        while(!pq.empty()){
            int now;
            ll time;
            tie(time, now) = pq.top(); pq.pop();
            if(dist[now] != time)continue;

            for(auto [cost, nxt] : g[now]){
                if(time + cost < dist[nxt]){
                    dist[nxt] = time + cost;
                    pq.push(make_pair(dist[nxt], nxt));
                }
            }
        }
        return dist;
    };

    vector<vector<ll>> dist(N);
    rep(i,N)dist[i] = dijkstra(i);

    int st = K + N, en = K + N + 1;
    mcf_graph<int,ll> mg(K + N + 2);
    rep(i,K) mg.add_edge(st, i, 1, 0ll);
    rep(j,N) mg.add_edge(j + K, en, B[j], 0ll);
    rep(i,K)rep(j,N) mg.add_edge(i, j + K, 1, dist[A[i] - 1][j]);

    auto res = mg.flow(st, en, K);
    cout << res.second << endl;
}