#include <bits/stdc++.h>
using namespace std;

struct DATA{
    int i;
    long long w;
    long long maxx;

    bool operator <(const DATA & d2) const{
        return w < d2.w;
    }
};

vector<pair<int,long long>>g[100100];
priority_queue<DATA>pq;

long long dis[100100];
pair<int,long long> from[100100];
int main(){

    int n,m,u,v,s,t;
    long long w,ans=0;
    scanf(" %d %d",&n,&m);
    scanf(" %d %d",&s,&t);
    for(int i = 1;i<=m;i++){
        scanf(" %d %d %lld",&u,&v,&w);
        ans += w;
        g[u].push_back({v,w});
        g[v].push_back({u,w});
    }

    for(int i = 0;i<=n;i++) dis[i] = 1e9;
    dis[s] = 0;
    pq.push({s,(long long)0,(long long)0});

    while(!pq.empty()){
        DATA f = pq.top();
        pq.pop();
        //cout << f.i << " " << f.w << " " << f.maxx <<endl;
        for(auto x : g[f.i]){
            int to = x.first;
            w = x.second;
            //cout << "to " << to << " " << w << endl;
            if(f.w + w - max(w,f.maxx) < dis[to]){
                dis[to] = f.w + w - max(w,f.maxx);
                pq.push({to,f.w + w,max(f.maxx,w)});
                //cout << "Push " << to << " " << dis[to] << " " << f.w + w - max(w,f.maxx) << endl;
            }
        }
    }
    //cout << dis[t] << endl;
    printf("%lld",ans-dis[t]);
}