#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pii pair<int,int>
#define int long long
const int mn = 2e5 + 5, inf = 2e18;
int n, m, k, d[3][mn], dp[mn];
vector <pii> a[mn], b[mn];
void dijkstra(int aa, int d[]){
fill(d, d + mn, inf);
d[aa] = 0;
priority_queue <pii, vector <pii>, greater <pii>> pq;
pq.push({d[aa], aa});
while(pq.size()){
int u = pq.top().se;
int c = pq.top().fi;
pq.pop();
if(d[u] < c) continue;
for(auto i : a[u]){
int v = i.fi, w = i.se;
if(d[v] > w + c){
d[v] = w + c;
// cout << aa << ' ' << d[v] << '\n';
pq.push({d[v], v});
}
}
}
}
void solve(){
cin >> n >> m;
int aa, bb, cc, dd; cin >> aa >> bb >> cc >> dd;
vector <pair<pii, int>> edges;
for(int i = 1; i <= m; i++){
int u, v, c; cin >> u >> v >> c;
a[u].push_back({v, c});
a[v].push_back({u, c});
}
dijkstra(aa, d[1]);
dijkstra(bb, d[2]);
priority_queue <pii, vector <pii>, greater<pii>> pq;
int path = d[1][bb];
fill(dp, dp + mn, inf);
dp[cc] = 0;
pq.push({dp[cc], cc});
while(pq.size()){
int c, u;
tie(c, u) = pq.top();
pq.pop();
if(c > dp[u]) continue;
for(auto i : a[u]){
int v = i.fi, w = i.se;
if(d[1][u] + w + d[2][v] == path){
if(dp[v] > dp[u]){
dp[v] = dp[u];
pq.push({dp[v], v});
}
}
else{
if(dp[v] > dp[u] + w){
dp[v] = dp[u] + w;
pq.push({dp[v], v});
}
}
}
}
cout << dp[dd];
}
signed main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
if(fopen("tunnel.inp", "r")){
freopen("tunnel.inp", "r", stdin);
freopen("tunnel.out", "w", stdout);
}
int t = 1;
// cin >> t;
while(t--) solve();
return 0;
}
