#include<bits/stdc++.h>
#define double long double
#define int128 __int128
#define int long long
#define re register
#define in inline
#define Pi pair<int,int>
#define vi vector<int>
#define max(a,b)  ((a)>(b)?a:b)
#define min(a,b)  ((a)<(b)?a:b)
#define ls x<<1
#define rs x<<1|1
#define mid (l+r>>1)
#define dx x+xx[i]
#define dy y+yy[i]
#define debug cout<<"wuyu"<<endl;
using namespace std;
const int INF=0x3f3f3f3f3f;
const int N=1e5+19;
const int M=1e6+10;
const int mod=998244353;
const double eps=1e-5;
in int read(){	re int x=0,f=0;re char c=getchar();	while(!isdigit(c)) f|=(c=='-'),c=getchar();	while(isdigit(c))  x=(x<<3)+(x<<1)+c-'0',c=getchar();	return f?-x:x;}
in void write(re int x){	if(x<0) putchar('-'),x=-x;	if(x>9) write(x/10);	putchar(x%10+'0');}


struct edge{
	int u,v,w;
	int nx;
}e[M];
int tot,head[N];


in void add(re int u,re int v,re int w){
	e[++tot].u=u;
	e[tot].v=v;
	e[tot].w=w;
	e[tot].nx=head[u];
	head[u]=tot;
}


struct node{
	int val,id,num;
	bool operator<(const node&a)const{
		return val<a.val;
	}
	node(int id,int val,int num){
		id=id;val=val;num=num;
		return;
	}
};

priority_queue<node>q;

int n,m,k;
bool vis[N][20];
int d[N][21];

void dij(){
	for(int i=1;i<=n;i++){
		for(int j=0;j<=k;j++){
			d[i][j]=INF;
		}
	}
	d[1][0]=0;
	q.push(node(1,0,0));
	
	while(!q.empty()){
		node kk=q.top();
		q.pop();
		int u=kk.id,num=kk.num;
		if(vis[u][num]) continue;
		vis[u][num]=1;
		
		for(int i=head[u];i;i=e[i].nx){
			int v=e[i].v;
			if(d[v][num]>max(d[u][num],e[i].w)){
				d[v][num]=max(d[u][num],e[i].w);
				if(!vis[v][num]){
					q.push(node(v,d[v][num],num));
				}
				if(num<k&&d[v][num+1]>d[u][num]){
					d[v][num+1]=d[u][num];
					if(!vis[v][num+1]){
						q.push(node(v,d[v][num+1],num+1));
					}
				}
			}
		}
	}
}


signed main(){
	n=read();m=read();k=read();
	for(int i=1;i<=m;i++){
		int u,v,w;
		u=read();v=read();w=read();
		add(u,v,w);add(v,u,w);
	}
	
	dij();
	
	if(d[n][k]!=INF){
		cout<<d[n][k]<<endl;
	}
	else{
		cout<<-1<<endl;
	}
	
	return 0;
}