N,M = map(int,input().split())
UV = [list(map(int,input().split())) for _ in range(M)]
P = [[0] * N for _ in range(N)]
for u,v,c in UV:
    P[u][v] = max(P[u][v], c)

dp = [-1] * (1 << N)
for i in range(N):
    dp[1<<i] = 0
for _ in range(N):
    for i in range(N):
        for j in range(N):
            for k in range(1<<N):
                if k & (1<<i) and not(k & (1<<j)) and dp[k] >= 0:
                    dp[k|(1<<j)] = max(dp[k|(1<<j)],dp[k] + P[i][j])
print(dp[-1])