#include<bits/stdc++.h>
#define int long long
#define pi pair<int,int>
using namespace std;
const int N=5e5+5;
struct node{
    int to,nxt,w;
}e[N];
int head[N],cnt;
void add(int u,int v,int w){
    e[++cnt]={v,head[u],w};
    head[u]=cnt;
}
int n,q,m;
int a[N],b[N],val[N];
set<pi> s[N];
int du[N];
int LIM=400;
bool heavy[N];
vector<pi> l_edge[N],path,EDGE[N];
vector<int> heavy_nodes;
const int mod=998244353;
map<pi,int> dis;
void Nth_element(int u,int l,int r,int k){
    if(l==r) return;
    int rd=l+rand()%(r-l);
    swap(EDGE[u][rd],EDGE[u][l]);
    pi key=EDGE[u][l];
    int i=l,j=r;
    while(i<j){
        while(i<j && EDGE[u][j] >=key) j--;
        EDGE[u][i]=EDGE[u][j];
        while(i<j && EDGE[u][i] <key) i++;
        EDGE[u][j]=EDGE[u][i];
    }
    EDGE[u][i]=key;
    if(i==k-1) return;
    else if(i>k-1) Nth_element(u,l,i-1,k);
    else Nth_element(u,i+1,r,k);
}
void update_heavy(){
    for(auto u:heavy_nodes){
        Nth_element(u,0,EDGE[u].size()-1,LIM+1);
    }
}
signed main(){
    scanf("%lld%lld%lld",&n,&m,&q);
    for(int i=1;i<=n;i++) scanf("%lld",&a[i]);
    for(int i=1,u,v,w;i<=m;i++){
        scanf("%lld%lld%lld",&u,&v,&w);
        du[u]++;du[v]++;
        add(u,v,w);add(v,u,w);
        EDGE[u].push_back({w,v});EDGE[v].push_back({w,u});
        dis[{u,v}]=dis[{v,u}]=w;
    }
    for(int i=1;i<=n;i++){
        if(du[i]>=LIM){
            heavy[i]=1;
            heavy_nodes.push_back(i);
        }
    }
    for(int i=1;i<=q;i++) scanf("%lld",&b[i]);
    for(int j=q;j>=1;j--){
        int u=b[j];
        if(j%LIM==0) update_heavy();
        int minv=-1,minn=1e18;
        if(heavy[u]){
            for(int i=0;i<=min(LIM,(int)EDGE[u].size()-1);i++){
                pi x=EDGE[u][i];
                if(x.first+val[x.second]<minn){
                    minn=x.first+val[x.second];
                    minv=x.second;
                }
            }
            path.push_back({u,minv});
        }
        else{
            for(int i=head[u];i;i=e[i].nxt){
                int v=e[i].to;
                if(e[i].w+val[v]<minn){
                    minn=e[i].w+val[v];
                    minv=v;
                }
            }
            path.push_back({u,minv});
        }
        val[u]=minv;
    }
    long long ans=0;
    for(int i=path.size()-1;i>=0;i--){
        int u=path[i].first,v=path[i].second;
        ans=(ans+a[u]*dis[{u,v}])%mod;
        a[v]=(a[v]+a[u])%mod;a[u]=0;
        // printf("! %d %d\n",path[i].first,path[i].second);
    }
    printf("%lld\n",ans);
    return 0;
}