#include<iostream>
#include<fstream>

using namespace std;

int v[20][20],nr_vf,nr_muchii,x,y;

int Adancime(int nod,int drum){
     int i;

     for(i=1;i<=nr_vf;i++){

        if(v[nod][i]){
            if(nod<i)
                drum=drum+v[nod][i];
            if(nod>i)
                drum=drum-v[nod][i];
           // cout<<endl<<drum;
            v[nod][i]=v[i][nod]=0;
        if(i!=y)
            Adancime(i,drum);
        else
            return drum;

            break;
        }
     }
}

void Citire(){
    int i,j;
    ifstream f("sate.in");
    f>>nr_vf>>nr_muchii;
    f>>x>>y;
    cout<<"Numar de varfuri: "<<nr_vf<<endl<<"Numar de muchii: "<<nr_muchii<<endl;
    for(int k=1;k<=nr_muchii;k++){
        f>>i;
        f>>j;
        f>>v[i][j];
        v[j][i]=v[i][j];
    }
}

void Afisare(){
    for(int i=1;i<=nr_vf;i++){
        cout<<endl;
        for(int j=1;j<=nr_vf;j++){
            if(v[i][j]<9)
                cout<<" ";
            cout<<v[i][j]<<" ";
        }
    }
}

int main(){

    Citire();
    Afisare();
    ofstream g(sate.out);
    g<<Adancime(x,0);
    cout<<endl<<endl<<"Drumul de la "<<x<<" la "<<y<<": "<<Adancime(x,0);
    cout<<endl;
    //Afisare();


return 0;}