#! ruby
# yukicoder My Practice
# author: Leonardone @ NEETSDKASU
############################################################
def gs() gets.chomp end
def gi() gets.to_i end
def gf() gets.to_f end
def gss() gs.split end
def gis() gss.map(&:to_i) end
def gfs() gss.map(&:to_f) end
def nmapf(n,f) n.times.map{ __send__ f } end
def ngs(n) nmapf n,:gs end
def ngi(n) nmapf n,:gi end
def ngss(n) nmapf n,:gss end
def ngis(n) nmapf n,:gis end
def arr2d(h,w,v=0) h.times.map{[v] * w} end
def for2p(hr,wr,&pr) hr.each{|i|wr.each{|j| yield(i,j)}} end
def nsum(n) n * (n + 1) / 2 end
def vcount(d,r=Hash.new(0)) d.inject(r){|r,e| r[e]+=1;r} end
############################################################

require 'matrix'

n, m = gis

ar = arr2d(n,n)

ngis(m).each do |a,b,c|
    a -= 1
    b -= 1
    ar[a][b] = c
    ar[b][a] = c
end

n.times do |i|
    ar[i][i] = - ar[i].inject(:+)
end

mt = Matrix.rows(ar)

p mt.eigen.eigenvalues.count(0)