#ifndef LOCAL
#define FAST_IO
#endif
// ============
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cmath>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#define OVERRIDE(a, b, c, d, ...) d
#define REP2(i, n) for (i32 i = 0; i < (i32) (n); ++i)
#define REP3(i, m, n) for (i32 i = (i32) (m); i < (i32) (n); ++i)
#define REP(...) OVERRIDE(__VA_ARGS__, REP3, REP2)(__VA_ARGS__)
#define PER(i, n) for (i32 i = (i32) (n) - 1; i >= 0; --i)
#define ALL(x) begin(x), end(x)
using namespace std;
using u32 = unsigned int;
using u64 = unsigned long long;
using u128 = __uint128_t;
using i32 = signed int;
using i64 = signed long long;
using i128 = __int128_t;
using f64 = double;
using f80 = long double;
template <typename T>
using Vec = vector<T>;
template <typename T>
bool chmin(T &x, const T &y) {
if (x > y) {
x = y;
return true;
}
return false;
}
template <typename T>
bool chmax(T &x, const T &y) {
if (x < y) {
x = y;
return true;
}
return false;
}
istream &operator>>(istream &is, i128 &x) {
i64 v;
is >> v;
x = v;
return is;
}
ostream &operator<<(ostream &os, i128 x) {
os << (i64) x;
return os;
}
istream &operator>>(istream &is, u128 &x) {
u64 v;
is >> v;
x = v;
return is;
}
ostream &operator<<(ostream &os, u128 x) {
os << (u64) x;
return os;
}
[[maybe_unused]] constexpr i32 INF = 1000000100;
[[maybe_unused]] constexpr i64 INF64 = 3000000000000000100;
struct SetUpIO {
SetUpIO() {
#ifdef FAST_IO
ios::sync_with_stdio(false);
cin.tie(nullptr);
#endif
cout << fixed << setprecision(15);
}
} set_up_io;
// ============
#ifdef DEBUGF
#else
#define DBG(x) (void) 0
#endif
constexpr i32 SZ = 4;
bool update(array<Vec<pair<i64, i32>>, SZ> &dist, i32 v, i64 d, i32 f) {
REP(i, SZ) {
if (dist[i][v].second == f) {
if (d >= dist[i][v].first) {
return false;
}
dist[i][v].first = d;
i32 cur = i;
while (cur > 0 && dist[cur - 1][v].first > dist[cur][v].first) {
swap(dist[cur - 1][v], dist[cur][v]);
--cur;
}
return true;
}
}
if (d >= dist[SZ - 1][v].first) {
return false;
}
dist[SZ - 1][v] = pair<i64, i32>(d, f);
i32 cur = SZ - 1;
while (cur > 0 && dist[cur - 1][v].first > dist[cur][v].first) {
swap(dist[cur - 1][v], dist[cur][v]);
--cur;
}
return true;
}
int main() {
i32 n, m, k;
cin >> n >> m >> k;
Vec<Vec<pair<i32, i64>>> g(n);
REP(ei, m) {
i32 u, v, w;
cin >> u >> v >> w;
--u;
--v;
g[u].emplace_back(v, w);
g[v].emplace_back(u, w);
}
Vec<i32> a(k);
REP(i, k) {
cin >> a[i];
--a[i];
}
array<Vec<pair<i64, i32>>, SZ> dist;
fill(ALL(dist), Vec<pair<i64, i32>>(n, pair<i64, i32>(INF64, -1)));
priority_queue<tuple<i64, i32, i32>> pq;
REP(i, k) {
dist[0][a[i]] = pair<i64, i32>(0, i);
pq.emplace(0, i, a[i]);
}
while (!pq.empty()) {
auto [d, f, v] = pq.top();
pq.pop();
d *= -1;
bool found = false;
REP(i, SZ) {
if (dist[i][v] == pair<i64, i32>(d, f)) {
found = true;
}
}
if (!found) {
continue;
}
for (auto &[u, w] : g[v]) {
if (update(dist, u, d + w, f)) {
pq.emplace(-(d + w), f, u);
}
}
}
array<Vec<pair<i64, i32>>, SZ> adist;
fill(ALL(adist), Vec<pair<i64, i32>>(k, pair<i64, i32>(INF64, -1)));
REP(i, 4) REP(j, k) {
adist[i][j] = dist[i][a[j]];
}
i64 closest = INF64;
i32 cu = -1, cv = -1;
REP(i, k) {
if (chmin(closest, adist[1][i].first)) {
cu = i;
cv = adist[1][i].second;
}
}
i64 exmin = INF64;
REP(i, k) {
if (i == cu || i == cv) {
continue;
}
REP(j, 1, 4) {
if (adist[j][i].second != cu && adist[j][i].second != cv) {
chmin(exmin, adist[j][i].first);
}
}
}
i64 ans = closest + exmin;
REP(i, 2, 4) REP(j, 2, 4) {
if (adist[i][cu].second != adist[j][cv].second) {
chmin(ans, adist[i][cu].first + adist[j][cv].first);
}
}
cout << ans << '\n';
}
