#include<iostream>
#include<queue>
#include<cstring> 
using namespace std;
int n,m,k,a,b,c,dis[2500001],ckd[2500001],s,t;
int to[2500001],nextt[2500001],head[2500001],w[2500001],cnt;
void add_edge(int x,int y,int wa){
	to[cnt]=y;
	w[cnt]=wa;
	nextt[cnt]=head[x];
	head[x]=cnt++;
}
struct Node{
	int id;
	Node(int a):id(a){}
	bool friend operator < (Node a,Node b){
		return dis[a.id]>dis[b.id];
	}
};
priority_queue<Node> q;
void dijk(){
	while(!q.empty()){
		Node aaa=q.top();
		q.pop(); 
		if(ckd[aaa.id]==1)continue;
		ckd[aaa.id]=1;
		for(int j=head[aaa.id];j!=-1;j=nextt[j]){
			//if(w[j]==0x3f)continue;
			if(dis[to[j]]>dis[aaa.id]+w[j]){
				dis[to[j]]=dis[aaa.id]+w[j];
				q.push(Node(to[j]));
				//break;
			}
		}
	}
}
int main(){
	cin>>n>>m>>k>>s>>t;
	memset(head,-1,sizeof(head));
	memset(dis,0x3f,sizeof(dis));
	for(int i=0;i<m;i++){
		cin>>a>>b>>c;
		add_edge(a,b,c);
        add_edge(b,a,c);
		for(int j=1;j<=k;j++){
			add_edge(j*n+a,j*n+b,c);
            add_edge(j*n+b,j*n+a,c);
			add_edge((j-1)*n+a,j*n+b,0); 
			add_edge((j-1)*n+b,j*n+a,0); 
		}
	}
	dis[s]=0;
	q.push(Node(s));
	for(int i=1;i<=k;i++){
		add_edge((i-1)*n+t,i*n+t,0);
	}
	dijk();
	cout<<dis[k*n+t];
	return 0;
}

救命实在看不出来在哪里错了，恳请大佬指点

感激不尽