class DisjointsetUnionFind:
    def __init__(self, N: int):
        self.number = N
        self.parent = [ -1 for _ in range(self.number + 1)]
        self.size = [ 1 for _ in range(self.number + 1)]
 
    def rootsearch(self, x):
        while True:
            if self.parent[x] == -1:
                break
            else:
                x = self.parent[x]
        return x
     
    def leader_size(self, v : int):
        return self.size[self.rootsearch(v)]
 
    def union(self, u: int, v: int):
        ru = self.rootsearch(u)
        rv = self.rootsearch(v)
        if ru != rv:
            if self.size[ru] < self.size[rv]:
                self.parent[ru] = rv
                self.size[rv] += self.size[ru]
            else:
                self.parent[rv] = ru
                self.size[ru] += self.size[rv]
 
    def issame(self, u: int, v: int):
        return self.rootsearch(u) == self.rootsearch(v)
 
N, M = list(map(int,input().split()))
Vertex_list = list()
for i in range(M):
    a, b, w = list(map(int,input().split()))
    Vertex_list.append([a - 1, b - 1, w])
Vertex_list.sort(key = lambda x : -x[2])
 
uf = DisjointsetUnionFind(N)
union_size = 1
answer = 0
while union_size < N:
    p = Vertex_list.pop()
    if not uf.issame(p[0], p[1]):
        answer += uf.leader_size(p[0]) * uf.leader_size(p[1]) * p[2]
        uf.union(p[0], p[1])
        union_size += 1
 
print(answer)