#include<cstring>
#include<iostream>

using namespace std;

const int N = 20010, M = 2e5 + 10;

int n, m;
int e[M], ne[M], w[M], h[N], idx;
int color[N];

void add(int a, int b, int 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; // 注意这块一定不能是<=
        int j = e[i];
        if(color[j]) {
            if(color[j] == color[u])
                return false;
        }
        else if(!dfs(j, 3 - c, mid))
            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() {
    scanf("%d%d", &n, &m);
    memset(h, -1, sizeof h);
    while(m --) {
        int a, b, c;
        scanf("%d%d%d", &a, &b, &c);
        add(a, b, c), add(b, a, c);
    }
    int l = 0, r = 1e9;
    while(l + 1 < r) {
        int mid = l + r >> 1;
        if(check(mid)) r = mid;
        else l = mid;
    }
    cout << l << endl;
    return 0;
}