#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n,m;
cin >> n >> m;
int s,t;
cin >> s >> t;
int u,v;
cin >> u >> v;
s --;
t --;
u --;
v --;
assert(s == u);
vector<vector<pair<int,int>>> adj(n);
for(int i = 0;i < m;i++){
int a,b,w;
cin >> a >> b >> w;
a --;
b --;
adj[a].push_back({b,w});
adj[b].push_back({a,w});
}
const i64 inf = 1e18;
function<vector<i64>(int)> f = [&](int src){
priority_queue<pair<i64,int>,vector<pair<i64,int>>,greater<pair<i64,int>>> pq;
vector<i64> dist(n,inf);
dist[src] = 0LL;
pq.push({0LL,src});
while(!pq.empty()){
auto p = pq.top();
pq.pop();
int a = p.second;
i64 c = p.first;
for(auto pp : adj[a]){
int vv = pp.first;
int w = pp.second;
if(dist[vv] > c + w){
dist[vv] = c + w;
pq.push({c + w,vv});
}
}
}
return dist;
};
vector<i64> distx = f(s);
vector<i64> disty = f(t);
priority_queue<pair<i64,int>,vector<pair<i64,int>>,greater<pair<i64,int>>> pq;
vector<i64> dist(n,inf);
for(int i = 0;i < n;i++){
if(distx[i] + disty[i] == distx[t]){
pq.push({0LL,i});
dist[i] = 0LL;
}
}
while(!pq.empty()){
auto p = pq.top();
pq.pop();
int a = p.second;
i64 c = p.first;
for(auto pp : adj[a]){
int vv = pp.first;
int w = pp.second;
if(dist[vv] > c + w){
dist[vv] = c + w;
pq.push({c + w,vv});
}
}
}
cout << dist[v] << '\n';
return 0;
}
