// INOI1402
 
#include <iostream>
//#include <limits>
 
using namespace std;
 
unsigned long computemaxcost(unsigned long arr[][231],unsigned long c, unsigned long int f);
unsigned long selectminburntime(unsigned long [], unsigned long[], unsigned long);
 
int main()
{
	unsigned long c,f;
	cin>>c>>f;
 
	unsigned long arr[231][231];
 
	for(unsigned long i = 1; i<= c; i++)
	for(unsigned long j = 1; j<=c; j++)
	arr[i][j] = 0;
 
	unsigned long k,l;
 
	for(unsigned long i = 1; i<=f; i++)
	{
		 cin>>k>>l;
		 cin>>arr[k][l];
		 arr[l][k] = arr[k][l];
	}
 
	unsigned long max = computemaxcost(arr,c,f);
 
	cout<<max;
 
	return 0;
}
 
unsigned long computemaxcost(unsigned long arr[231][231], unsigned long int c,unsigned long f)
{
	unsigned long expectedburntime[231];
	unsigned long burnt[231];
	unsigned long max = 0, k = 1;
 
	while(k<=c){
	   for(unsigned long i = 1; i<=c; i++)
	   {
		burnt[i] = 0;
		expectedburntime[i] = 100002;
	   }
 
	expectedburntime[k] = 0;
 
	unsigned long i = selectminburntime(burnt,expectedburntime,c);
 
	while(i)
	{
		burnt[i] = 1;
		for(unsigned long j = 1; j<= c; j++)
		{
			if(arr[i][j] != 0 && burnt[j]!=1 && expectedburntime[i]+arr[i][j] < expectedburntime[j])
			{
				expectedburntime[j] = expectedburntime[i]+arr[i][j];
			}
		}
		i = selectminburntime(burnt,expectedburntime,c);
	}
 
	for(unsigned long ip = 1; ip<=c; ip++)
	{
		if(expectedburntime[ip]>max)
		{
			max = expectedburntime[ip];
		}
	}
 
	k++;
   }
 
   return max;
}
 
unsigned long selectminburntime(unsigned long burnt[], unsigned long expectedburntime[],unsigned long c)
{
	unsigned long pos = 0;
	unsigned long minburn = 32767;
 
	  for(unsigned long i = 1; i<=c; i++)
	  {
		if((!burnt[i])  &&  (expectedburntime[i] < minburn))
	  	{
			minburn = expectedburntime[i];
			pos = i;
		  }
	   } 
 
	return pos;
}