N,M=map(int, input().split())

D=[[] for i in range(N)]
for i in range(M):
  a,b,c=map(int,input().split())
  a-=1;b-=1
  D[a].append((b,c))
  D[b].append((a,c))
  
from collections import deque
d=deque()
#,1は行きがけ、,0は帰りがけ
d.append((0,1,0))


V=[0]*N
ans=0;f=0
while d:
  now,x,c=d.pop()
  if x==1:
    f+=c
    ans=max(ans,2*f)
    V[now]=1
    d.append((now,0,c))
    for nex,c in D[now]:
      if V[nex]==0:
        d.append((nex,1,c))
  else:
    V[now]=0
    f-=c
print(ans)