#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e5 + 5;
const ll INF = 1e18;
int n, m, s, t, U, V;
vector<pair<int, int>> adj[N];
ll dis[2][N], ans, dp[2][N], d[N];
bool vst[N];
void dij1(int st, int id) {
for (int i = 1; i <= n; i++) {
dis[id][i] = INF;
vst[i] = false;
}
dis[id][st] = 0;
priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> q;
q.push({0, st});
while (!q.empty()) {
int u = q.top().second;
q.pop();
if (vst[u]) continue;
vst[u] = true;
for (auto it : adj[u]) {
int v = it.first;
int w = it.second;
if (dis[id][v] > dis[id][u] + w) {
dis[id][v] = dis[id][u] + w;
q.push({dis[id][v], v});
}
}
}
}
void dij2(int st, int en) {
for (int i = 0; i <= n; i++) {
vst[i] = false;
dp[0][i] = dp[1][i] = INF;
d[i] = INF;
}
priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> q;
d[st] = 0;
q.push({0, st});
dp[0][st] = dis[0][st];
dp[1][st] = dis[1][st];
while (!q.empty()) {
int u = q.top().second;
q.pop();
if (vst[u]) continue;
vst[u] = true;
for (auto it : adj[u]) {
int v = it.first;
int w = it.second;
if (d[v] > d[u] + w) {
d[v] = d[u] + w;
dp[0][v] = min(dis[0][v], dp[0][u]);
dp[1][v] = min(dis[1][v], dp[1][u]);
q.push({d[v], v});
} else if (d[v] == d[u] + w) {
if (min(dis[0][v], dp[0][u]) + min(dis[1][v], dp[1][u]) < dp[0][v] + dp[1][v]) {
dp[0][v] = min(dis[0][v], dp[0][u]);
dp[1][v] = min(dis[1][v], dp[1][u]);
}
}
}
}
ans = min(ans, dp[0][en] + dp[1][en]);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> m >> s >> t >> U >> V;
for (int i = 1; i <= m; i++) {
int u, v, w;
cin >> u >> v >> w;
adj[u].push_back({v, w});
adj[v].push_back({u, w});
}
dij1(U, 0);
dij1(V, 1);
ans = dis[0][V];
dij2(s, t);
if (ans != INF) cout << ans;
else cout << -1;
return 0;
}
