#include <bits/stdc++.h>
#define MAX 101000
bool rota[MAX];
typedef std::pair<long long,long long> pii;
typedef std::pair<long long,pii> pip;
std::vector<long long> veio[MAX];
std::map<long long,bool> mapa[MAX];
std::vector<long long> levou[MAX];
std::vector<pii> con[MAX];
bool dp_check[MAX],dp_res[MAX];
long long S,T,U,V;
bool dp(int x){
if(dp_check[x])return dp_res[x];
dp_check[x]=true;
for(auto&z:veio[x]){
if(dp(z)){
dp_res[x]=rota[x]=true;
}
}
return dp_res[x];
}
long long valextra[MAX],pesmin[MAX];
long long inf =1000000000000000000LL;
long long dpb[MAX],dpu[MAX],cup[MAX],cbai[MAX];
long long dpbai(int x) {
if(cbai[x])return dpb[x];
dpb[x]=inf;
cbai[x]=true;
long long min = pesmin[x];
for(auto&z:veio[x]) {
if(rota[z])
min=std::min(min,dpbai(z));
}
return dpb[x]=min;
}
long long dpup(int x) {
if(cup[x])return dpu[x];
dpu[x]=inf;
cup[x]=true;
long long min = pesmin[x];
for(auto&z:levou[x]) {
if(rota[z]&&mapa[x].find(z)==mapa[x].end())
min=std::min(min,dpup(z));
}
return dpu[x]=min;
}
int main()
{
std::ios::sync_with_stdio(false);
std::cin.tie(0);
std::cout.tie(0);
int N,M;
std::cin>>N>>M;
std::cin>>S>>T>>U>>V;--S;--T;--U;--V;
for(int i=0;i!=M;++i){
long long a,b,c;
std::cin>>a>>b>>c;--a;--b;
con[a].push_back({b,c});
con[b].push_back({a,c});
}
///Rotas
{
bool visitou[N]={};
long long custos[N]={};for(auto&x:custos)x=inf;
std::priority_queue<pip,std::vector<pip>,std::greater<pip>> queue;
queue.push({0LL,{S,S}});
while(queue.size()){
auto _ = queue.top();
queue.pop();
auto custo = _.first;
auto atual = _.second.first;
auto prev = _.second.second;
if(custos[atual]>=custo){
veio[atual].push_back(prev);
mapa[atual][prev]=true;
levou[prev].push_back(atual);
}
if(visitou[atual])continue;
visitou[atual]=true;
custos[atual]=custo;
for(auto&x:con[atual]){
queue.push({custo+x.second,{x.first,atual}});
}
}
dp_res[S]=dp_check[S]=rota[S]=true;
dp(T);
}
///Peso Minimo para V
{
bool visitou[N]={};
std::priority_queue<pii,std::vector<pii>,std::greater<pii>> queue;
queue.push({0LL,V});
while(queue.size()){
auto _ = queue.top();
queue.pop();
auto custo = _.first;
auto atual = _.second;
if(visitou[atual])continue;
visitou[atual]=true;
pesmin[atual]=custo;
for(auto&x:con[atual]){
queue.push({custo+x.second,x.first});
}
}
}
///Caminhos Minimos (2 DPs)
{
for(int i=0;i!=N;++i){
if(rota[i]){
valextra[i]=std::min(dpup(i),dpbai(i));
}
}
}
bool visitou[N]={};
std::priority_queue<pii,std::vector<pii>,std::greater<pii>> queue;
queue.push({0LL,U});
while(queue.size()){
auto _ = queue.top();
queue.pop();
auto custo = _.first;
auto atual = _.second;
if(visitou[atual])continue;
visitou[atual]=true;
if(atual==V){
std::cout<<custo<<"\n";
return 0;
}
if(rota[atual]){
queue.push({custo+valextra[atual],V});
}
for(auto&x:con[atual]){
queue.push({custo+x.second,x.first});
}
}
assert(0);
std::cout<<"-1\n";
}
