#include <iostream>
#include <vector>
#include <map>
#include <queue>
#include <functional>
using namespace std;
#define int long long
int N, M;
int S, T;
int U, V;
vector<map<int, int>> G;
class Node{
public:
int cost, node, from;
const bool operator>(const Node& o) const{
return cost > o.cost;
}
const bool operator>=(const Node& o) const{
return cost >= o.cost;
}
const bool operator<=(const Node& o) const{
return cost <= o.cost;
}
const bool operator<(const Node& o) const{
return cost < o.cost;
}
};
vector<bool> is_in_solut(vector<vector<int>> G, int node){
vector<bool> visited(N);
function<void(int)> dfs;
dfs = [&](int node){
if(visited[node])return;
visited[node] = true;
for(int next_node:G[node]){
if(!visited[next_node])
dfs(next_node);
}
};
dfs(node);
return visited;
}
signed main(){
cin >> N >> M;
cin >> S >> T;
cin >> U >> V;
for(int i=0; i<M; i++){
int node0, node1, cost;
cin >> node0 >> node1 >> cost;
G[node0][node1] = cost;
}
priority_queue<Node> Q;
vector<int> S_T(N);
vector<vector<int>> S_Tfrom(N);
Q.push({0, S, -1});
while(!Q.empty()){
Node cur=Q.top();
Q.pop();
if(S_T[cur.node] != -1){
if(S_T[cur.node] == cur.cost)
S_Tfrom[cur.node].push_back(cur.from);
continue;
}
if(cur.node == T)break;
S_T[cur.node] = cur.cost;
S_Tfrom[cur.node].push_back(cur.from);
for(auto A:G[cur.node]){
if(S_T[A.first] == -1)
Q.push({cur.cost+A.second, A.first, cur.node});
}
}
vector<bool> is_good = is_in_solut(S_Tfrom, T);
Q = priority_queue<Node>();
vector<int> U_V(N);
Q.push({0, V, -1});
while(!Q.empty()){
Node cur=Q.top();
Q.pop();
if(U_V[cur.node] != -1)
continue;
if(is_good[cur.node]){
cout << cur.cost << '\n';
return 0;
}
U_V[cur.node] = cur.cost;
for(auto A:G[cur.node]){
if(U_V[A.first] == -1)
Q.push({cur.cost+A.second, A.first, cur.node});
}
}
}
