def f(a):
    b=a
    a=A[a]
    while type(a)!=int:
        b=int(a)
        a=A[int(a)]
    return [a,b]
n,m=map(int,input().split())
D=[]
A=[None]+[1]*n
for i in range(1,m+1):
    a,b,w=map(int,input().split())
    D.append([w,a,b])
D.sort()
D=[None]+D
ans=0
for i in range(1,m+1):
    q=f(D[i][1])
    w=f(D[i][2])
    if q[1]==w[1]:
        div=0
    else:
        div=q[0]*w[0]
        A[q[1]]+=A[w[1]]
        A[w[1]]=str(q[1])
    ans+=D[i][0]*div
print(ans)