#include <bits/stdc++.h>
using namespace std;
const int v = 100;
int n , m , ans , e[v][v];
bool vis[v];
void dfs(int x , int len)
{
	int i ;
	vis[x] = 1;
	if(len > ans) ans = len;
	for(i = 1; i <= n; i++)
	
		if((!vis[i]) && (e[x][i] != -1))
		{
			cout << i << " = " << " " << e[x][i] << endl;
		dfs(i , len + e[x][i]);
		}
		vis[x] = 0;
	
}
int main()
{
	int i , j , a , b , c;
	cin >> n >> m;
	for(int i = 1; i <= n; i++)
	{
		for(int j = 1; j <= n; j++)
		e[i][j] = -1;
	}
	for(i = 1; i <= m; i++)
	{
		cin >> a >> b >> c;
		e[a][b] = c;
		e[b][a] = c;
	}
	for(int i = 1; i <= n; i++)
	{
		vis[i] = 0;
	}
	ans = 0;
	for(int i = 1; i <= n; i++)
	{
		dfs(i , 0);
	}
	cout << ans;
	return 0;
}

这个代码是干嘛的（感觉是在找最大路径），玄关！！