#include <bits/stdc++.h>
using namespace std;
#define int long long
vector<vector<pair<int, int>>> g;
vector<int> dist, dist2, travelling;
const int INF = 1e18 + 7;
signed main(){
int n, m; cin >> n >> m;
int s, t; cin >> s >> t;
int u, v; cin >> u >> v;
g.resize(n + 1);
dist.resize(n + 1, INF);
dist2.resize(n + 1, INF);
travelling.resize(n + 1, INF);
for (int i = 0; i < m; i++){
int a, b, c; cin >> a >> b >> c;
g[a].push_back({b, c});
g[b].push_back({a, c});
}
priority_queue<pair<int, int>> pq;
dist[s] = 0;
pq.push({0, s});
while(!pq.empty()){
int d = pq.top().first;
int v = pq.top().second;
pq.pop();
if (dist[v] != -d) continue;
for (auto [u, c] : g[v]){
if (-d + c < dist[u]){
pq.push({d - c, u});
dist[u] = -d + c;
}
}
}
dist2[t] = 0;
pq.push({0, t});
while(!pq.empty()){
int d = pq.top().first;
int v = pq.top().second;
pq.pop();
if (dist2[v] != -d) continue;
for (auto [u, c] : g[v]){
if (-d + c < dist2[u]){
pq.push({d - c, u});
dist2[u] = -d + c;
}
}
}
travelling[u] = 0;
pq.push({0, u});
while(!pq.empty()){
int d = pq.top().first;
int v = pq.top().second;
pq.pop();
if (travelling[v] != -d) continue;
for (auto [u, c] : g[v]){
if (dist[u] + dist2[v] + c == dist[t]){
if (-d < travelling[u]){
pq.push({d, u});
travelling[u] = -d;
}
}else if (dist[v] + dist2[u] + c == dist[t]){
if (-d < travelling[u]){
pq.push({d, u});
travelling[u] = -d;
}
}else{
if (-d + c < travelling[u]){
pq.push({d - c, u});
travelling[u] = -d + c;
}
}
}
}
/*for (int i = 1; i <= n; i++){
cout << dist[i] << ' ';
}
cout << endl;
for (int i = 1; i <= n; i++){
cout << dist2[i] << ' ';
}
cout << endl;*/
cout << travelling[v] << endl;
}
