#include<stdio.h>
#include<string.h>
#include<stdbool.h>

#define P 810
#define C 1460

int n, p, c;
int dist[P];
int st[P];

int h[P], cnt;
struct edge{
    int to;
    int next;
    int weight;
}E[C*2];

void add(int v, int w, int weight){
    E[++cnt].next = h[v];
    E[cnt].to = w;
    E[cnt].weight = weight;
    h[v] = cnt;
}

int que[P];
bool inQue[P];
int head, tail;

int spfa(int x){
    dist[x] = 0;
    que[++tail] = x, inQue[x] = true;

    while(head != tail){
       int t = que[++head];
       head %= P;
       inQue[t] = false;

       for(int i = h[t]; i != -1; i = E[i].next){
           int j = E[i].to;
           if(dist[j] > dist[t] + E[i].weight){
               dist[j] = dist[t] + E[i].weight;
               if(!inQue[j]){
                    que[++tail] = j;
                    tail %= P;
                    inQue[j] = true;
               }
           }
       }
    }

    int res = 0;
    for(int j = 1; j <= p; j++)
        if(st[j] > 0)  res += st[j]*dist[j];

    return res;
} 

int main(){

    scanf("%d %d %d", &n, &p, &c);
    memset(h, -1, sizeof h);

    for(int i = 1; i <= n; i++){
        int x;  scanf("%d", &x);
        st[x]++;
    }

    for(int i = 1; i <= c; i++){
        int a, b, w;
        scanf("%d %d %d", &a, &b, &w);
        add(a, b, w), add(b, a, w);
    }

    int min = 0x3f3f3f3f;
    for(int i = 1; i <= p; i++){
        head = 0, tail = 0;
        memset(inQue, false, sizeof inQue);
        memset(dist, 0x3f, sizeof dist);

        if(h[i] == -1) continue;   //最后有一个测试过不了 特判了一下

        int res = spfa(i);
        if(res < min) min = res;
    }

    printf("%d", min);

    return 0;
}