#include <bits/stdc++.h>
using namespace std;
typedef long long int lli;
typedef pair<lli,lli> pii;
vector<vector<pii> > adj;
void dijk(int start,vector<lli>& dist,vector<lli>& pre){
set<pii> nodes;
int len=dist.size();
dist=vector<lli>(len,1e17);
nodes.insert(pii(0,start));
dist[start]=0;
pre=vector<lli>(len,-1);
while(!nodes.empty())
{
auto sim=*nodes.begin();
nodes.erase(sim);
for(auto u:adj[sim.second]){
if(dist[sim.second]+u.second<dist[u.first]){
if(nodes.find(pii(dist[u.first],u.first))!=nodes.end())
nodes.erase(pii(dist[u.first],u.first));
dist[u.first]=dist[sim.second]+u.second;
pre[u.first]=sim.second;
nodes.insert(pii(dist[u.first],u.first));
}
}
}
}
vector<vector<pii> > gdag(100006,vector<pii>());
vector<lli> in(100006,0);
/*void eliminate(int node,vector<vector<pii> >& dag){
marked2[node]=true;
for (auto u:dag[node])
{
gdag[u.first].push_back(pii(node,u.second));
//cout << "gdag'a ekledi: "<<u.first <<"->"<<node<<"\n";
if(!marked2[u.first])eliminate(u.first,dag);
}
}*/
/*
* */
typedef pair<lli,pii> data;
lli ans=1e17;
void dfs(int node,vector<vector<pii> >& dag,vector<lli>& upminv,vector<lli>& upminu,vector<lli>& distu,vector<lli>& distv){
//cout << "sh dag: "<<node<<"\n";
//cout << "upminu: "<<upminu[node]<<" upminv: "<<upminv[node]<<"\n";
upminu[node]=min(upminu[node],distu[node]);
upminv[node]=min(upminv[node],distv[node]);
ans=min(ans,distv[node]+upminu[node]);
ans=min(ans,distu[node]+upminv[node]);
for (auto kms:dag[node])
{
in[kms.first]--;
upminv[kms.first]=min(upminv[kms.first],upminv[node]);
upminu[kms.first]=min(upminu[kms.first],upminu[node]);
if(in[kms.first]<=0)dfs(kms.first,dag,upminv,upminu,distu,distv);
//cout << node<<"->"<<kms.first<<"\n";
}
}
int main(){
int n,m;
cin>>n>>m;
lli s,t,u,v;
cin>>s>>t>>u>>v;
adj=vector<vector<pii> >(n+1,vector<pii>());
for (int i = 0; i < m; i++)
{
int a,b,c;
cin>>a>>b>>c;
adj[a].push_back(pii(b,c));
adj[b].push_back(pii(a,c));
}
vector<lli> distu(n+1),distv(n+1),preu(n+1),prev(n+1), dists(n+1),pres(n+1),distt(n+1),pret(n+1);
dijk(s,dists,pres);
dijk(t,distt,pret);
vector<vector<pii> > dag(n+1,vector<pii>()),dagters(n+1,vector<pii>());
for(int i=1;i<=n;i++){
for (auto nodi:adj[i])
{
if(nodi.second+dists[i]+distt[nodi.first]==dists[t]){
dag[i].push_back(pii(nodi.first,nodi.second));
dagters[nodi.first].push_back(pii(i,nodi.second));
in[nodi.first]++;
}
}
}
dijk(u,distu,preu);
dijk(v,distv,prev);
vector<lli> upminv(n+1,1e15),upminu(n+1,1e15),upminvters(n+1,1e15),upminuters(n+1,1e15);
upminv[s]=distv[s];
upminu[s]=distu[s];
upminu[s]=distu[s];
upminv[s]=distv[s];
ans=distv[u];
if(in[s]!=0){
//cout << "bozuk\n";
return -1;
}
dfs(s,dag,upminv,upminu,distu,distv);
cout<<ans<<"\n";
return 0;
}
