n, m = map(int, input().split())
score = [[0]*n for _ in range(n)]
for _ in range(m):
    a, b, s = map(int, input().split())
    score[a][b] = s

dp = [[0]*n for _ in range(1 << n)]
for s in range(1 << n):
    for v in range(n):
        for u in range(n):
            if not (s >> u) & 1:
                continue
            if (s >> v) & 1 == 0:
                if dp[s][u]+score[u][v] > dp[s | (1 << v)][v]:
                    dp[s | (1 << v)][v] = dp[s][u]+score[u][v]

print(max(dp[(1 << n)-1]))