#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

ifstream in ("berarii2.in");
ofstream out ("berarii2.out");

#define MAX_N 30001
bool viz[MAX_N];

struct zdrang
{
    int cost, directie;
};

vector<zdrang> graf[MAX_N];
vector<int> ans;

int dfs(int node, int cost)
{
    for(int i = 0; i < graf[node].size(); ++i)
    {
        zdrang next = graf[node][i];
        //cout << next << " ";
        if(!viz[next])
        {
            viz[next] = 1;
            dfs(next);
        }
    }
}

int main()
{
    int n, m, x, y, a, b, d;
    in >> n >> m >> x >> y;
    for(int i = 0; i < m; ++i)
    {
        in >> a >> b >> d;
        graf[a].push_back({d, b});
        graf[b].push_back({-d, a});
    }


    return 0;
}