#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;
using ll = long long;

#include<queue>
#include<atcoder/scc>
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);


    ll n,m,q;
    cin>>n>>m>>q;
    vector<vector<int>> g(n);
    vector<ll> u(m),v(m),w(m);
    for(int i = 0;i<m;i++){
        cin>>u[i]>>v[i]>>w[i];
        u[i]--;v[i]--;
        g[u[i]].push_back(i);
     //   s.add_edge(u[i],v[i]);
    }
    vector<int> now(m,0);
    // auto use = s.scc();
    // vector<int> cnt(n,0);
    // for(int i = 0;i<use.size();i++) for(auto ni:use[i]) cnt[ni] = i;
    // for(int i = 0;i<n;i++) cout<<i<<" "<<cnt[i]<<endl;

    while(q--){
        {
            int j;
            cin>>j;
            j--;
            now[j] ^= 1;
        }
        atcoder::scc_graph s(n);
        {
            for(int i = 0;i<m;i++) if(now[i]==0) s.add_edge(u[i],v[i]);

        }
        auto use = s.scc();
        vector<int> cnt(n,0);
        for(int i = 0;i<use.size();i++) for(int j:use[i]) cnt[j] = i;
        vector<ll> can(n,-1e18);
        can[0] = 0;
        for(auto p:use){
            priority_queue<pair<ll,ll>> que;
            for(int j:p) if(can[j]!=-1e18) que.push({can[j],j});
            while(que.size()){
                int ni = que.top().second;
                auto nn = que.top();
                que.pop();
                if(nn.first!=can[ni]) continue;
                for(auto id:g[ni]){
                    int to = v[id];
                    if(now[id]==1) continue;
                    if(cnt[to]==cnt[ni]){
                        if(can[to]<can[ni]+w[id]){
                            can[to] = can[ni] + w[id];
                            que.push({can[to],to});
                        }
                    }else{
                        can[to] = max(can[to],can[ni]+w[id]);
                    }
                }
            }
        }
        ll ans = can[n-1];
        if(ans==-1e18) cout<<"Nan\n";
        else cout<<ans<<endl;
        //return 0;
    }
}