from collections import defaultdict

def culc_inc(n, m):
    if m in D[n]:
        return D[n][m]
    else:
        return 0

def insertion():
    sum = 0
    L = [NL.pop()]
    while NL:
        inc = 0
        inc_L = 0
        inc_R = 0
        max_inc = 0
        max_index = 0
        n = NL.pop()
        for i in reversed(range(len(L))):
            inc_R = culc_inc(L[i], n) + inc_L
            inc_L = culc_inc(n, L[i]) + inc_L
            inc = max(inc_L, inc_R)
            if inc > max_inc:
                max_inc = inc
                max_index = (i+1 if inc_L < inc_R else i)
            else:
                max_inc += culc_inc(L[i], n)
        L.insert(max_index, n)
        sum += max_inc
    return sum

N, M = map(int,input().split())
NL = [i for i in range(N)]
D = defaultdict(dict)

for i in range(M):
    item1, item2, score = map(int,input().split())
    D2 = {item2: score}
    D[item1].update(D2)

print(insertion())