#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin() , v.end()
#define ios ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
#define int long long

using namespace std;

typedef long long LL;
typedef pair<int , int> PII;

const int N = 1e5 + 5;
const int mod = 998244353;
const int INF = 1e18;
vector<PII>g[N];

void solve()
{
    int n,m,q;
    cin>>n>>m>>q;
    vector<int>nb(q+1,0),a(n+1,0),cnt(n+1,0);
    for(int i=1;i<=n;i++)   cin>>a[i];
    for(int i=1;i<=m;i++)
    {
        int u,v,w;
        cin>>u>>v>>w;
        g[u].push_back({w,v});
        g[v].push_back({w,u});
    }
    for(int i=1;i<=q;i++)   cin>>nb[i];
    for(int i=1;i<=n;i++)   sort(all(g[i]));
    vector<int>b(1,0);
    for(int i=1;i<=q;i++)
    {
        b.push_back(nb[i]);
        int j=i;
        while(j+1<=q&&nb[j]==nb[j+1])j++;
        i=j;
    }
    q = b.size()-1;
    __int128 res=0;
    vector<PII>query(q+1,{0,0});
    for(int i=q;i>=1;i--)
    {
        int u = b[i];
        int w = g[b[i]][0].x,v = g[b[i]][0].y;
        int minv = INF,vt=-1,wt=-1;
        for(auto it : g[u])
        {
            int w = it.x,v = it.y;
            if(cnt[v]+w<minv)
            {
                minv = cnt[v]+w;
                vt=v;
                wt=w;
            }
        }
        cnt[u]=cnt[v]+w;
        query[i]={vt,wt};
             
    }   
    // __int128 res=0;
    // for(int i=1;i<=n;i++)   res+=(__int128)cnt[i]*a[i];
    
    for(int i=1;i<=q;i++)
    {
        int u = b[i],v = query[i].x,w= query[i].y;
        res+=a[u]*w;
        a[v]+=a[u],a[u]=0;
        //cout<<u<<" "<<v<<" "<<w<<"\n";
    }
    int ans = res%mod;
    cout<<ans<<"\n";
    

}

signed main(){
    ios;
    int T = 1;
    //cin >> T;
    while(T --){
        solve();
    }
    return 0;
}

/*
2
SPR
SPSRRP
*/