#include <fstream>
#include <vector>
#include <queue>
#include <climits>
using namespace std;
ifstream fin ("dijkstra.in");
ofstream fout ("dijkstra.out");
int n,m,p,l,k;
const int nmax=50005,inf=INT_MAX;
vector < pair <int,int> > muchii[nmax];
int dist[nmax];
bool inCoada[nmax];
struct cmp
{
    bool operator () (int x,int y)
    {
        return dist[x]>dist[y];
    }
};
priority_queue <int,vector<int>,cmp> q;
void solve0()
{
    for (int i=1;i<=n;i++)
    {
        dist[i]=inf;
    }
    dist[1]=0;
    q.push(1);
    inCoada[1]=true;
    while (!q.empty())
    {
        int nod=q.top();
        q.pop();
        inCoada[nod]=false;
        for (int i=0;i<muchii[nod].size();i++)
        {
            int vecin=muchii[nod][i].first;
            int cost=muchii[nod][i].second;
            if (dist[nod]+cost<dist[vecin])
            {
                dist[vecin]=dist[nod]+cost;
                if (!inCoada[vecin])
                {
                    q.push(vecin);
                    inCoada[vecin]=true;
                }
            }
        }
    }
    fout << dist[n];
}
int main()
{
    fin >> n >> m >> p >> l >> k;
    for (int i=1;i<=m;i++)
    {
        int x,y,c;
        fin >> x >> y >> c;
        muchii[x].push_back(make_pair(y,c));
        muchii[y].push_back(make_pair(x,c));
    }
    if (k==0) solve0();
}