n,m=tuple(map(int,input().split()))
way=[set() for i in range(n)]
for i in range(m):
	inp=tuple(map(int,input().split()))
	way[inp[0]-1].add((inp[1]-1,inp[2]))
	way[inp[1]-1].add((inp[0]-1,inp[2]))
def longest(fr,to,without):
	maxd=0
	for i in way[fr]:
		if not (i[0] in without):
			d=i[1]+longest(i[0],to,without+[fr])
			if d>maxd:
				maxd=d
	return maxd
maxd=0
for i in range(n):
	for j in range(m):
		if i==j:
			continue
		d=longest(i,j,[])
		if maxd<d:
			maxd=d
print(maxd)