#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define f first
#define s second
#define pb push_back
#define p push
#define pii pair<int,int>
#define ppii pair<int,pii>
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
#define set(x) memset(x,-1,sizeof(x));
const int mxn=1e5+1,mod=1e9+7;
#define int long long
int n,m,s,t,u,v,sz,cost,ans=-1;
vector<int> pa[mxn+10];
vector<pii>adj[mxn+10];
vector<bitset<mxn+10>>path;
bitset<mxn+10>vis,vis2[mxn+10];
void dijk(){
vector<int>dist(n+1,-1);
priority_queue<pii,vector<pii>,greater<pii>>pq;
dist[s]=0;
pq.p({0,s});
while(!pq.empty()){
int cur=pq.top().s;
pq.pop();
if(vis[cur])continue;
if(cur==t)break;
vis[cur]=true;
for(auto i:adj[cur]){
if(dist[i.f]==-1||dist[i.f]>dist[cur]+i.s){
dist[i.f]=dist[cur]+i.s;
pa[i.f].clear();
pa[i.f].pb(cur);
pq.p({dist[i.f],i.f});
}
else if(dist[i.f]==dist[cur]+i.s)pa[i.f].pb(cur);
}
}
}
void solve(){
vector<vector<int>>dp(n+1,vector<int>(sz+1,-1));
priority_queue<ppii,vector<ppii>,greater<ppii>>pq;
for(int i=0;i<path.size();i++)pq.p({0,{u,i}}),dp[u][i]=0;
while(!pq.empty()){
int cur=pq.top().s.f,comp=pq.top().s.s;
pq.pop();
if(cur==v){
if(ans==-1)ans=dp[cur][comp];
else ans=min(ans,dp[cur][comp]);
continue;
}
if(vis2[cur][comp])continue;
vis2[cur][comp]=true;
for(auto i:adj[cur]){
cost=i.s;
if(path[comp][cur]&&path[comp][i.f]){
cost=0;
}
if(dp[i.f][comp]==-1||dp[i.f][comp]>dp[cur][comp]+cost)dp[i.f][comp]=dp[cur][comp]+cost,pq.p({dp[i.f][comp],{i.f,comp}});
}
}
}
int32_t main(){
fastio
cin>>n>>m>>s>>t>>u>>v;
while(m--){
int a,b,c;cin>>a>>b>>c;
adj[a].pb({b,c});
adj[b].pb({a,c});
}
queue<pair<int,bitset<mxn+10>>>q;
dijk();
vis.reset();
q.p({t,vis});
while(!q.empty()){
q.front().s[q.front().f]=true;
for(auto i:pa[q.front().f])q.p({i,q.front().s});
if(q.front().f==s)path.pb(q.front().s);
q.pop();
}
solve();
cout<<ans;
return 0;
}
