#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define X first
#define Y second
#define maxs(a,b) (a=max(a,b))
#define mins(a,b) (a=min(a,b))
#define lc id<<1
#define rc lc|1
#define mid ((l+r)>>1)
#define pb push_back
const int MXN = 1e5+5;
const int MXK = 4;
int n, k, m, V[MXK], root;
vector<pii> g[MXN];
ll dp[1<<MXK][MXN];
priority_queue<pll> pq;
int32_t main() {
cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
cin >> n >> k >> m >> root; k--;
for(int i=0; i<k; i++) cin >> V[i];
for(int i=0,u,v,w; i<m; i++) {
cin >> u >> v >> w;
g[u].pb(pii(v,w));
g[v].pb(pii(u,w));
}
for(int msk=1; msk<(1<<k); msk++)
fill(dp[msk]+1, dp[msk]+n+1, 2e18);
for(int msk=0; msk<(1<<k); msk++) {
for(int v=1; v<=n; v++) {
for(int smsk=(msk-1)&msk; smsk; smsk=(smsk-1)&msk)
mins(dp[msk][v], dp[smsk][v]+dp[msk^smsk][v]);
pq.push(pll(-dp[msk][v], v));
}
while(!pq.empty()) {
ll d = -pq.top().X;
int v = pq.top().Y;
pq.pop();
if(d!=dp[msk][v]) continue;
for(auto [u, w] : g[v])
if(dp[msk][u]>d+w)
pq.push(pll(-(dp[msk][u]=d+w), u));
}
for(int i=0; i<k; i++)
mins(dp[msk|(1<<i)][V[i]], dp[msk][V[i]]);
}
cout << dp[(1<<k)-1][root] << '\n';
return 0;
}
