I,R=input,range
def J():
	return map(int,I().split())
N,M=J()
p=[i for i in R(N)]
c=[1]*N
def r(i):
	m=p[i]
	while i!=m:
		p[i]=i=p[m]
		m=p[i]
	return i
E=[0]*M
for i in R(M):
	a,b,w=J()
	E[i]=w,a-1,b-1
E.sort()
s=0
for i in R(M):
	w,a,b=E[i]
	a,b=r(a),r(b)
	if a!=b:
		s,c[b],p[a]=s+c[a]*c[b]*w,c[b]+c[a],b
print(s)