#include<bits/stdc++.h>
using namespace std;
int n,m,k,S,T,hd[100005],nxt[100005],ver[100005],val[100005],vis[100005],idx,tmp[15];
int ans=INT_MAX;
void add(int x,int y,int z){
    ver[++idx]=y;
    val[idx]=z;
    nxt[idx]=hd[x];
    hd[x]=idx;
}
void dfs(int x,int jiu[15],int cs,int xie){
    if (cs>n) return;
    if (x==T){
        int sum=0;
        for (int i=1;i<=k;i++){
            sum+=jiu[i];
        }
        ans=min(ans,xie-sum);
        return;
    }
    for (int i=hd[x];i;i=nxt[i]){
        int y=ver[i];
        if (vis[y]==1) continue;
        int v=val[i];
        int tjiu[15];
        for (int j=1;j<=10;j++){
            tjiu[j]=jiu[j];
        }
        for (int j=1;j<=10;j++){
            if (v>tjiu[j]){
                for (int l=j+1;l<=10;l++){
                    tjiu[l]=tjiu[l-1];
                }
                tjiu[j]=v;
                break;
            }
        }
        vis[y]=1;
        dfs(y,tjiu,cs+1,xie+v);
        vis[y]=0;
    }
}
int main(){
    freopen("move.in","r",stdin);
    freopen("move.out","w",stdout);
    scanf("%d%d%d",&n,&m,&k);
    scanf("%d%d",&S,&T);
    for (int i=1;i<=m;i++){
        int a,b,c;
        scanf("%d%d%d",&a,&b,&c);
        add(a,b,c);
        add(b,a,c);
    }
    vis[S]=1;
    dfs(S,tmp,0,0);
    printf("%d",ans);
    return 0;
}