package com.jd;

import java.io.BufferedInputStream;

import java.util.Scanner;

public class Main2 {

public static void main(String[] args) {

Scanner in = new Scanner(new BufferedInputStream(System.in));

int n = in.nextInt();

int m = in.nextInt();

int[][] array = new int[n + 1][n + 1];

for (int t = 0; t < m; t++) {

int i = in.nextInt();

int j = in.nextInt();

int val = in.nextInt();

array[i][j] = val;

array[j][i] = val;

}

int maxWeight = 0;

int result = 0;

for (int i = 1; i <= n; i++) {

int temp = 0;

int j = i;

int count = m - 1;

while (count > 0) {

count--;

temp = Integer.MAX_VALUE;

;

if (array[j%(n + 1)][(j + 1)%(n + 1)] < temp) {

temp = array[j%(n + 1)][(j + 1)%(n + 1)];

}

j++;

}

if (temp > result) result = temp;

}

System.out.println(result);

}

}