2019.03.18_B

#include <bits/stdc++.h>

#define F first
#define S second
#define ll long long
#define ull unsigned long long
#define ld long double
#define SELO ""
#define openfiles ifstream cin("input"  SELO  ".txt"); ofstream cout("output"  SELO  ".txt");
#define faster ios_base::sync_with_stdio(NULL); cin.tie(0); cout.tie(0);
#define all(x) x.begin(), x.end()

using namespace std;

vector <ll> pos, swords, shields, used, order, pred, loop, hard, mx_Shield, mx_Sword;
vector <ll> v[200000], rev_v[200000];
vector <pair <ll, ll> > type;
vector <ll> new_type;
vector <ll> new_Graph[200000];

void dfs1(ll fr)
{
    used[fr] = 1;
    for(auto to : v[fr])
        if(!used[to])
            dfs1(to);
    order.push_back(fr);
}

void dfs2(ll fr)
{
    used[fr] = 1;
    for(auto to : rev_v[fr])
        if(!used[to])
            dfs2(to);
    hard.push_back(fr);
}

void dfs3(ll fr)
{
    used[fr] = 1;
    if(new_type[fr] == 2)
        pred[fr] = max(pred[fr], mx_Sword[fr] * mx_Shield[fr]);
    for(auto to : new_Graph[fr])
    {
        if(!used[to])
            dfs3(to);
        pred[fr] = max(pred[fr], pred[to]);
        pred[fr] = max(pred[fr], max(mx_Sword[fr] * mx_Shield[to], mx_Shield[fr] * mx_Sword[to]));
        mx_Sword[fr] = max(mx_Sword[fr], mx_Sword[to]);
        mx_Shield[fr] = max(mx_Shield[fr], mx_Shield[to]);
    }
}

int main()
{
    openfiles
    ll n, m, k;
    cin >> n >> m >> k;
    pos.resize(k);
    swords.resize(n);
    shields.resize(n);
    loop.resize(n);
    for(int i = 0; i < k; i++)
         cin >> pos[i];
    for(int i = 0; i < n; i++)
        cin >> swords[i];
    for(int i = 0; i < n; i++)
        cin >> shields[i];
    for(int i = 0; i < m; i++)
    {
        int l, r;
        cin >> l >> r;
        if(l == r)
            loop[l] = 1;
        v[l - 1].push_back(r - 1);
        rev_v[r - 1].push_back(l - 1);
    }
    used.assign(n, 0);
    mx_Shield.assign(n, 0);
    mx_Sword.assign(n, 0);
    type.resize(n);
    for(int i = 0; i < n; i++)
        if(!used[i])
            dfs1(i);
    used.assign(n, 0);
    int cl = 0;
    for(int i = n - 1; i >= 0; i--)
        if(!used[order[i]])
        {
            dfs2(order[i]);
            int tp = 0;
            if(hard.size() > 1 || loop[hard[0]] == 1)
                tp = 2;
            else
                tp = 1;
            for(int j = 0; j < hard.size(); j++)
            {
                type[hard[j]] = {cl, tp};
                mx_Shield[cl] = max(mx_Shield[cl], shields[hard[j]]);
                mx_Sword[cl] = max(mx_Sword[cl], swords[hard[j]]);
            }
            hard.clear();
            new_type.push_back(tp);
            cl++;
        }
    used.assign(n, 0);
    pred.assign(cl, 0);
    for(int i = 0; i < n; i++)
    {
        for(auto j : v[i])
            if(type[j].F != type[i].F)
                new_Graph[type[i].F].push_back(type[j].F);
    }
    for(int i = 0; i < n; i++)
        if(!used[i])
            dfs3(i);
    ll ans = 0;
    for(int i = 0; i < k; i++)
        ans += pred[type[pos[i] - 1].F];
    cout << ans;
}