#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<ll,ll>
const ll MX = 1e5 + 5, INF = 1e18;
vector<pair<ll,ll>> adj[MX];
vector<array<int,3>> edges(MX);
vector<ll> distS(MX, INF);
vector<ll> distT(MX, INF);
vector<ll> dist(MX, INF);
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
ll n,m;
cin >> n >> m;
ll s,t,u,v;
cin >> s >> t >> u >> v;
for(int a,b,c,i = 1 ; i <= m ; i++)
{
cin >> a >> b >> c;
adj[a].push_back({b,c});
adj[b].push_back({a,c});
edges[i] = {a,b,c};
}
priority_queue<pii,vector<pii>, greater<pii>> pq;
distS[s] = 0;
pq.push({0,s});
while(!pq.empty()){
ll cost = pq.top().first, V = pq.top().second;
pq.pop();
if(distS[V] != cost){
continue;
}
for(auto U : adj[V])
{
ll nxt = U.first, w = U.second;
if(distS[nxt] > cost + w)
{
distS[nxt] = cost + w;
pq.push({distS[nxt],nxt});
}
}
}
ll sp = distS[t];
distT[t] = 0;
pq.push({0,t});
while(!pq.empty()){
ll cost = pq.top().first, V = pq.top().second;
pq.pop();
if(distT[V] != cost){
continue;
}
for(auto U : adj[V])
{
ll nxt = U.first, w = U.second;
if(distT[nxt] > cost + w)
{
distT[nxt] = cost + w;
pq.push({distT[nxt],nxt});
}
}
}
for(int i = 1 ; i<= m ; i++){
ll a,b,c;
a = edges[i][0], b =edges[i][1], c = edges[i][2];
if((distS[a] + distT[b] + c == sp )||(distS[b] + distT[a] + c == sp) ){
//cout <<" y";
adj[a].push_back({b,0});
adj[b].push_back({a,0});
}
}
dist[u] = 0;
pq.push({0,u});
while(!pq.empty()){
ll cost = pq.top().first, V = pq.top().second;
pq.pop();
if(dist[V] != cost){
continue;
}
for(auto U : adj[V])
{
ll nxt = U.first, w = U.second;
if(dist[nxt] > cost + w)
{
dist[nxt] = cost + w;
pq.push({dist[nxt],nxt});
}
}
}
cout << dist[v];
return 0;
}
