#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000000

int main(){
	
	int N,M,T;
	cin>>N>>M>>T;
	
	vector dis(N,vector<int>(N,Inf));
	rep(i,M){
		int a,b,c;
		cin>>a>>b>>c;
		a--;b--;
		dis[a][b] = c;
		dis[b][a] = c;
	}
	rep(i,N)dis[i][i] = 0;
	
	rep(i,N){
		rep(j,N){
			rep(k,N){
				dis[j][k] = min(dis[j][k], dis[j][i]+dis[i][k]);
			}
		}
	}
	
	vector<int> v(T);
	rep(i,T){
		cin>>v[i];
		v[i]--;
	}
	sort(v.begin(),v.end());
	
	vector<int> cov;
	rep(i,N){
		if(!binary_search(v.begin(),v.end(),i))cov.push_back(i);
	}
	int ans = Inf;
	if(T<=15){
		vector dp(N,vector<int>(1<<T,Inf));
		rep(i,N){
			dp[i][0] = 0;
			
			rep(j,T){
				dp[i][1<<j] = dis[i][v[j]];
			}
		}
		rep(i,1<<T){
			if(__builtin_popcount(i)<=1)continue;
			for(int S = i&(i-1);S!=0;S = (S-1)&i){
				rep(j,N){
					dp[j][i] = min(dp[j][i],dp[j][S] + dp[j][S^i]);
				}				
			}
			rep(j,N){
				rep(k,N){
					dp[j][i] = min(dp[j][i],dp[k][i] + dis[k][j]);
				}
			}
		}
		rep(i,N)ans = min(ans,dp[i].back());
	}
	else{
		vector<pair<int,pair<int,int>>> E;
		rep(j,N){
			for(int k=j+1;k<N;k++){
				E.emplace_back(dis[j][k],make_pair(j,k));
			}
		}
		sort(E.begin(),E.end());
		vector<bool> f(N,false);
		rep(i,v.size())f[v[i]] = true;
		rep(i,1<<cov.size()){
			rep(j,cov.size()){
				if((i>>j)&1)f[cov[j]] = true;
			}
			
			dsu D(N);
			
			int temp = 0;
			rep(j,E.size()){
				int x = E[j].second.first,y = E[j].second.second;
				if(f[x]&&f[y]){
					if(!D.same(x,y)){
						D.merge(x,y);
						temp += E[j].first;
					}
				}
			}
			ans = min(ans,temp);
			rep(j,cov.size()){
				if((i>>j)&1)f[cov[j]] = false;
			}
		}
	}
	
	cout<<ans<<endl;
	
	return 0;
}