from collections import defaultdict
import sys

sys.setrecursionlimit(10 ** 6)

def dfs(i, vst, d=0):
    mx = d
    for ki, kd in to[i]:
        if ki in vst: continue
        vst.add(ki)
        tmp = dfs(ki, vst, d + kd)
        vst.remove(ki)
        if tmp > mx:
            mx = tmp
    return mx

n, m = map(int, input().split())
to = defaultdict(list)
for _ in range(m):
    a, b, c = map(int, input().split())
    a -= 1
    b -= 1
    to[a].append([b, c])
    to[b].append([a, c])
print(max(dfs(i,set([i])) for i in range(n)))