#pragma GCC optimize("Ofast")
#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#ifdef ENABLE_DEBUG
#include <debug.h>
#else
#define DEBUG(...) do {} while (0)
#endif
using namespace std;
using namespace __gnu_pbds;
using ll = long long;
using ull = unsigned long long;
using lll = __int128;
using ulll = unsigned __int128;
using ld = long double;
template<typename T, size_t N> using ar = array<T, N>;
template<typename T, typename Cmp = less<T>>
using iset = tree<T, null_type, Cmp, rb_tree_tag,
tree_order_statistics_node_update, allocator<T>>;
#define REPSI(name, start, stop, step) for (ll name = start; name < (ll)stop; name += step)
#define REPS(name, start, stop) REPSI(name, start, stop, 1)
#define REP(name, stop) REPS(name, 0, stop)
#define RREPSI(name, start, stop, step) for (ll name = stop-1; name >= (ll)start; name -= step)
#define RREPS(name, start, stop) RREPSI(name, start, stop, 1)
#define RREP(name, stop) RREPS(name, 0, stop)
template<typename T> void cins(T &first) { cin >> first; }
template<typename T, typename... Ts> void cins(T &first, T &second, Ts&... rest) {
cin >> first;
cins(second, rest...);
}
#define GET(type, ...) type __VA_ARGS__; cins(__VA_ARGS__)
#define GETI(...) GET(int, __VA_ARGS__)
#define GETLL(...) GET(ll, __VA_ARGS__)
#define GETS(...) GET(string, __VA_ARGS__)
#define GETD(...) GET(double, __VA_ARGS__)
#define GETC(...) GET(char, __VA_ARGS__)
struct hsh {
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
x += FIXED_RANDOM;
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
};
const ll INF = 1LL<<60;
const int mxN = 1e5;
vector<ar<ll, 2>> g[mxN];
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template<class IsStart, class IsTarget>
ar<ll, 3> solve(ll n, IsStart is_start, IsTarget is_target, ll cut) {
vector<bool> vis(n);
priority_queue<ar<ll, 3>, vector<ar<ll, 3>>, greater<ar<ll, 3>>> pq;
REP(i, n) if (is_start(i)) pq.push({0, i, i});
while (pq.size()) {
auto [dhere, cur, source] = pq.top();
pq.pop();
if (dhere > cut) return {INF, -1, -1};
if (vis[cur]) continue;
if (is_target(cur)) return {dhere, cur, source};
vis[cur] = true;
for (auto [nxt, w] : g[cur]) {
if (vis[nxt]) continue;
pq.push({dhere+w, nxt, source});
}
}
return {INF, -1, -1};
}
int main() {
ios::sync_with_stdio(0);cin.tie(0);
auto t0 = chrono::steady_clock::now();
GETI(n, m, k);
REP(mm, m) {
GETI(i, j, w); --i, --j;
g[i].push_back({j, w});
g[j].push_back({i, w});
}
vector<ll> a(k), pof(n, -1);
REP(i, k) cin >> a[i], --a[i];
ll ans = INF;
while (true) {
auto t1 = chrono::steady_clock::now();
if (chrono::duration_cast<chrono::milliseconds>(t1-t0).count() > 5500) break;
shuffle(a.begin(), a.end(), rng);
REP(i, k) pof[a[i]] = i;
auto [d1, target1, source1] = solve(n,
[&](ll i){return pof[i] >= 0*k/4 && pof[i] < 1*k/4;},
[&](ll i){return pof[i] >= 2*k/4 && pof[i] < 3*k/4;},
ans
);
if (target1 == -1) continue;
auto [d2, target2, source2] = solve(n,
[&](ll i){return pof[i] >= 0*k/4 && pof[i] < 2*k/4 && i != target1 && i != source1;},
[&](ll i){return pof[i] >= 2*k/4 && pof[i] < 4*k/4 && i != target1 && i != source1;},
ans-d1
);
ans = min(ans, d1+d2);
}
cout << ans << '\n';
}
