#include <bits/stdc++.h>
#define smile "commuterpass."
#define mp make_pair
#define prior(type) priority_queue<type, vector<type>, greater<type> >
using namespace std;
using ll = long long;
using ii = pair<int, int>;
using lli = pair<ll, int>;
// using iii = tuple<int, int, int>;
const int N = (int) 1e5 + 10;
const ll inf = (ll) 1e15;
int n, m;
int s1, t1;
int s2, t2;
vector<ii> g[N];
namespace SUB1 // s1 == s2
{
vector<ll> d1, d2, d3;
bitset<N> vis;
void dijkstra(int s, vector<ll>& d)
{
d.assign(n+2, inf); vis.reset();
prior(lli) q;
q.push(mp(0LL, s));
d[s] = 0;
while (!q.empty())
{
int u = q.top().second;
q.pop();
if (vis[u]) continue;
vis[u] = 1;
for (ii t: g[u])
{
int v = t.second;
if (!vis[v] && d[v] > d[u] + t.first)
{
d[v] = d[u] + t.first;
q.push(mp(d[v], v));
}
}
}
}
void solve()
{
dijkstra(s1, d1);
dijkstra(t2, d2);
dijkstra(t1, d3);
ll ans = LLONG_MAX;
for (int y = 1; y <= n; y++)
if (d1[y] + d3[y] == d1[t1])
ans = min(ans, d2[y]);
cout << ans;
}
}
namespace SUB3
{
void solve()
{
}
}
namespace SUB2
{
vector<ll> d;
vector<int> trace;
bitset<N> vis;
set<int> free[N];
void dijkstra(int s, int t)
{
d.assign(n+2, inf); trace.assign(n+2, 0); vis.reset();
prior(lli) q;
q.push(mp(0, s));
d[s] = 0; trace[s] = -1;
while (!q.empty())
{
int u = q.top().second;
q.pop();
if (u == t) return;
if (vis[u]) continue;
vis[u] = 1;
for (ii x: g[u])
{
int v = x.second;
if (!free[u].empty())
{
if (free[u].find(v) != free[u].end())
x.first = 0;
}
if (!vis[v] && d[v] > d[u] + x.first)
{
d[v] = d[u] = x.first;
trace[v] = u;
q.push(mp(d[v], v));
}
}
}
}
void solve()
{
dijkstra(s1, t1);
// cerr << "ok";
for (int v = t1, u = trace[v]; v != s1 ; v = u, u = trace[v])
free[u].insert(v);
// cerr << u << ' ' << v << '\n';
// cerr << "\nok2";
dijkstra(s2, t2);
cout << d[t2];
}
}
int main()
{
//freopen(smile"inp", "r", stdin);
//freopen(smile"out", "w", stdout);
cin.tie(0) -> sync_with_stdio(0);
cin >> n >> m;
cin >> s1 >> t1;
cin >> s2 >> t2;
for (int i = 0; i < m; i++)
{
int a, b, c;
cin >> a >> b >> c;
g[a].push_back(mp(c, b));
g[b].push_back(mp(c, a));
}
// SUB2::solve();
if (s1 == s2)
SUB1::solve();
// else if (n <= 300)
// SUB3:: solve();
else
SUB2:: solve();
return 0;
}
