#include<iostream>
#include<vector>
#include<queue>
using namespace std;
int main()
{
cin.tie(nullptr)->sync_with_stdio(false);
int n,r;
cin>>n;
cin>>r;
vector<pair<int,int>> s;
vector<int> dist;
vector<vector<pair<int,int>>> adj(n);
int temp1,temp2;
cin>>temp1;
cin>>temp2;
s.push_back({temp1,temp2});
cin>>temp1;
cin>>temp2;
s.push_back({temp1,temp2});
for(int i=0;i<r;i++)
{
int u,v,w;
cin>>u;
cin>>v;
cin>>w;
u--;
v--;
adj[u].push_back({v,w});
adj[v].push_back({u,w});
}
/*for(int i=0;i<n;i++)
{
for(int j=0;j<adj[i].size();j++)
{
cout<<i<<" "<<adj[i][j].first<<" ";
}
cout<<"\n";
}*/
//////////////////////////////////////////////////////////
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>> > q;
dist.resize(n,1e9+7);
////////////////////////////////////////////////////////////////////
dist.assign(n,1e9+7);
dist[s[1].first-1]=0;
q.push({0,s[1].first-1});
while(!q.empty())
{
int a,b;
a=q.top().first;
b=q.top().second;
q.pop();
for(pair<int,int>& x:adj[b])
{
if(dist[x.first]<=x.second+a)
{
continue;
}
dist[x.first] = x.second+a;
q.push({dist[x.first], x.first});
}
}
int ans;
ans=dist[s[1].second-1];
cout<<ans;
}
