#include <bits/stdc++.h>

 using namespace std;

 struct edge{ int to,next,val; }e[];

 int n,p,C,a,b,c,tot,ans=1e9,i,j;

 int head[],rec[],d[][],v[];

 void add(int from,int to,int val)

 {

     e[++tot].to=to,e[tot].val=val;

     e[tot].next=head[from],head[from]=tot;

 }

 int main()

 {

     scanf("%d%d%d",&n,&p,&C);

     for(i=;i<=n;i++) scanf("%d",&a),rec[a]++;

     for(i=;i<=C;i++) scanf("%d%d%d",&a,&b,&c),add(a,b,c),add(b,a,c);

     memset(d,0x3f,sizeof(d));

     for(i=;i<=p;i++) {

         memset(v,,sizeof(v));

         queue<int> q;

         d[i][i]=;

         q.push(i); v[i]=;

         while(q.size()) {

             int x=q.front(); q.pop();

             v[x]=;

             for(j=head[x];j;j=e[j].next) {

                 int to=e[j].to,val=e[j].val;

                 if(d[i][to]>d[i][x]+val) {

                     d[i][to]=d[i][x]+val;

                     if(!v[to]) q.push(to),v[to]=;

                 }

             }

         }

     }

     for(i=;i<=p;i++) {

         int tmp=;

         for(j=;j<=p;j++)

             tmp=tmp+d[i][j]*rec[j];

         ans=min(ans,tmp);

     }

     printf("%d\n",ans);

     return ;

 }