#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long LL;
const int N = 2e4+10,M = 2e5+10;
int h[N], e[M], w[M], ne[M], idx;
int color[N];
int n,m;

void add(int a, int b, int c)  // 添加一条边a->b，边权为c
{
    e[idx] = b, w[idx] = c, ne[idx] = h[a], h[a] = idx ++ ;
}

bool dfs(int u,int c,int mid)
{
    color[u] = c;
    for(int i = h[u];~i;i = ne[i])
    {
        if(w[i] <= mid)continue;
        int j = e[i];
        if(!color[j])
        {
            if(!dfs(j,3-c,mid))return false;
        }
        else if(color[j] == c)return false;
    }
    return true;
}
bool check(int mid)
{
    memset(color,0,sizeof color);
    for(int i = 1;i<=n;i++)
    {
        if(!color[i])
        {
            if(!dfs(i,1,mid))return false;
        }
    }
    return true;
}
int main()
{
    memset(h, -1, sizeof h);
    cin>>n>>m;
    while(m--)
    {
        int a,b,c;
        cin>>a>>b>>c;
        add(a,b,c),add(b,a,c);
    }

    int l = 0,r = 1e9;
    while(l<r)
    {
        int mid = l + r >> 1;
        if(check(mid))r = mid;
        else l =  mid + 1;
    }
    cout<<l<<endl;
    return 0;
}