#include <bits/stdc++.h>
#define ve vector
#define ar array
#define pb push_back
#define ins insert
#define endl '\n'
#define ll long long
using namespace std;
const int MXN = 2e5+1;
int N, M;
int S, T;
int U, V;
ve<pair<int, ll>> adj[MXN];
void subtask1(){
set<ar<ll, 3>> pq;
ve<ll> distv(N+1, 1e18);
pq.insert({0, -1, V});
while(!pq.empty()){
auto [cst, _, sor] = *pq.begin();
pq.erase(pq.begin());
if(cst < distv[sor]){
distv[sor] = cst;
for(auto [x, c] : adj[sor]){
pq.insert({cst + c, _, x});
}
}
}
ve<ll> dists(N+1, 1e18);
ve<ll> ans(N+1, distv[S]+1);
pq.insert({0, distv[S], S});
while(!pq.empty()){
auto [cst, rel, sor] = *pq.begin();
pq.erase(pq.begin());
if(cst <= dists[sor] && rel < ans[sor]){
dists[sor] = cst;
ans[sor] = rel;
for(auto [x, c] : adj[sor]){
ll n_rel = min(rel, distv[x]);
pq.insert({cst + c, n_rel, x});
}
}
}
cout << ans[T] << endl;
}
void subtask2(){
map<pair<int, int>, bool> use_edge;
ve<ll> dsts(N+1, 1e18);
ve<ll> p(N+1, 0);
set<pair<ll, int>> pq;
pq.insert({0, S});
while(!pq.empty()){
auto top = *pq.begin();
pq.erase(pq.begin());
if(top.first < dsts[top.second]){
dsts[top.second] = top.first;
for(auto [x, c] : adj[top.second]){
if(top.first + c < dsts[x]){
p[x] = top.second;
pq.insert({top.first+c, x});
}
}
}
}
ve<ll> path;
int x = T;
while(x != S){
path.pb(x);
x = p[x];
}
path.pb(S);
reverse(path.begin(), path.end());
for(int i = 0; i < path.size()-1; i++){
adj[path[i]].pb({path[i+1], 0});
adj[path[i+1]].pb({path[i], 0});
}
ve<ll> dstv(N+1, 1e18);
pq.insert({0, V});
while(!pq.empty()){
auto top = *pq.begin();
pq.erase(pq.begin());
if(top.first < dstv[top.second]){
dstv[top.second] = top.first;
for(auto [x, c] : adj[top.second]){
if(top.first + c < dsts[x]){
p[x] = top.second;
pq.insert({top.first+c, x});
}
}
}
}
cout << dstv[U] << endl;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> N >> M;
cin >> S >> T;
cin >> U >> V;
for(int i = 0; i < M; i++){
int a, b, c;
cin >> a >> b >> c;
adj[a].pb({b, c});
adj[b].pb({a, c});
}
if(S==U){
subtask1();
}
else{
subtask2();
}
}
