///
/// ♪ Pizza mozzarella rella rella rella... ♪
///
#include <bits/stdc++.h>
#define Loop(x,l,r) for(ll x = ll(l); x < ll(r); ++x)
typedef long long ll;
typedef std::pair<ll,ll> pll;
using namespace std;
const int N = 100'010;
const ll inf = 1e15;
int n, m;
int s, t;
int u, v;
vector<ll> dij(vector<pll>* A, int s, int n, vector<int>* par = NULL)
{
vector<ll> dis(n);
set<pll> pq;
Loop(i,0,n) dis[i] = (i==s?0:inf);
pq.emplace(0,s);
while(pq.size())
{
auto v = pq.begin()->second;
pq.erase(pq.begin());
for(auto [u, w] : A[v])
{
if(dis[v] + w < dis[u])
{
if(par) par[u].clear();
pq.erase ({dis[u], u});
dis[u] = dis[v] + w;
pq.insert({dis[u], u});
}
if(dis[v] + w == dis[u] && par)
par[u].push_back(v);
}
}
return dis;
}
vector<pll> A[4*N];
vector<int> par[N];
bool vis[N];
void jotaro(int v)
{
vis[v] = 1;
for(auto p : par[v]){
A[n+p].emplace_back(n+v,0);
A[2*n+v].emplace_back(2*n+p,0);
if(!vis[p])
jotaro(p);
}
}
int main()
{
ios::sync_with_stdio(false); cin.tie(0);
cin >> n >> m >> s >> t >> u >> v;
--s; --t; --u; --v;
Loop(_,0,m)
{
int v, u, w;
cin >> v >> u >> w;
--v; --u;
A[v].emplace_back(u,w);
A[u].emplace_back(v,w);
A[3*n+v].emplace_back(3*n+u,w);
A[3*n+u].emplace_back(3*n+v,w);
}
dij(A, s, n, par);
jotaro(t);
Loop(i,0,n)
{
A[0*n+i].emplace_back(1*n+i, 0);
A[0*n+i].emplace_back(2*n+i, 0);
A[1*n+i].emplace_back(3*n+i, 0);
A[2*n+i].emplace_back(3*n+i, 0);
}
cout << dij(A, v, 4*n)[3*n+u] << '\n';
}
