from collections import defaultdict

class UnionFind():
  def __init__(self,n):
    self.n=n
    self.parents=[-1]*n

  def find(self,x):
    if self.parents[x]<0:
      return x
    else:
      self.parents[x]=self.find(self.parents[x])
      return self.parents[x]

  def union(self,x,y):
    x=self.find(x)
    y=self.find(y)

    if x==y:
      return

    if self.parents[x]>self.parents[y]:
      x,y=y,x

    self.parents[x]+=self.parents[y]
    self.parents[y]=x

  def size(self,x):
    return -self.parents[self.find(x)]

  def same(self,x,y):
    return self.find(x)==self.find(y)

  def members(self,x):
    root=self.find(x)
    return [i for i in range(self.n) if self.find(i)==root]

  def roots(self):
    return [i for i, x in enumerate(self.parents) if x< 0]

  def group_count(self):
    return len(self.roots())

  def all_group_members(self):
    group_members=defaultdict(list)
    for member in range(self.n):
      group_members[self.find(member)].append(member)
    return group_members

from sys import stdin
input=lambda :stdin.readline()[:-1]

n,m=map(int,input().split())
edge=[]
uf=UnionFind(n)
for _ in range(m):
  x,y,w=map(lambda x:int(x)-1,input().split())
  edge.append((w+1,x,y))
edge.sort(key=lambda x:x[0])
ans=0
for w,x,y in edge:
  if not uf.same(x,y):
    ans+=w*uf.size(x)*uf.size(y)
    uf.union(x,y)
print(ans)