#include<cstdio>

#include<cstring>

#include<algorithm>

const int M=;

using namespace std;

int read(){

    int ans=,f=,c=getchar();

    while(c<''||c>''){if(c=='-') f=-; c=getchar();}

    while(c>=''&&c<=''){ans=ans*+(c-''); c=getchar();}

    return ans*f;

}

struct node{int l,r,T;}e[M];

int cmp(node x,node y){return x.T<y.T;}

int n,m,ans=-,fa[M];

int find(int x){return fa[x]==x?x:fa[x]=find(fa[x]);}

int main(){

    n=read(); m=read();

    for(int i=;i<=n;i++) fa[i]=i;

    for(int i=;i<=m;i++) e[i].l=read(),e[i].r=read(),e[i].T=read();

    sort(e+,e++m,cmp);

//    for(int i=1;i<=m;i++) printf("%d %d %d\n",e[i].l,e[i].r,e[i].T);

    int cnt=n;

    for(int i=;i<=m;i++){

        int p=find(e[i].l),q=find(e[i].r);

        if(p!=q){

            cnt--;

            fa[p]=q;

        }

        if(cnt==){ans=e[i].T; break;}

    }

    printf("%d\n",ans);

    return ;

}