#include<bits/stdc++.h>
using namespace std;
const int inf=1e9;
const int maxn=10005,maxm=20005;
bool vis[maxn];
int  dis[maxn];
int head[2*maxm];
int Next[2*maxm];
int   to[2*maxm];
int  val[2*maxm];
typedef pair<int,int> pii;
queue<int> q;
int n,m,s,t,cnt=0;
void add_edge(int u,int v,int w)
{
    cnt++;
    to[cnt]=v;
    val[cnt]=w;
    Next[cnt]=head[u];
    head[u]=cnt;
}
bool prim(int up)
{
    memset(vis,false,sizeof(vis));
    q.push(s);
    while(!q.empty())
    {
        int pos=q.front();
        q.pop();
        if(vis[pos]==1)
        {
            continue;
        }
        vis[pos]=1;
        for(int i=head[pos];i;i=Next[i])
        {
            if(val[i]<=up&&vis[to[i]]==0)
            {
                if(to[i]==t)
                {
                    vis[t]=1;
                    break;
                }
                q.push(to[i]);
            }
        }
        if(vis[t]==1)
        {
            return 1;
        }
    }
    return 0;
}
int main()
{
    scanf("%d%d%d%d",&n,&m,&s,&t);
    int u,v,w;
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&u,&v,&w);
        add_edge(u,v,w);
        add_edge(v,u,w);
    }
    int l=1,r=10000;
    int ans=0x3f3f3f3f;
    while(l<=r)
    {
        int mid=(l+r)/2;
        if(prim(mid)==1)
        {
            ans=min(ans,mid);
            r=mid-1;
        }
        else
        {
            l=mid+1;
        }
    }
    printf("%d\n",ans);
    return 0;
}