#include<iostream>

 #include<cstdio>

 using namespace std;

 const int maxn = +;

 int n,m;

 int p[maxn],r[maxn];

 int finds(int x)

 {

     if(p[x]==x)  return x;

     int tmp = p[x];

     p[x] = finds(p[x]);

     r[x] = r[x] + r[tmp];

     return p[x];

 }

 void unions(int a, int b, int x, int y, int d)

 {

     p[x] = y;

     r[x] = d+r[b]-r[a];

 }

 int main()

 {

     //freopen("in.txt","r",stdin);

     while(~scanf("%d%d",&n,&m))

     {

         int ans = ;

         for(int i=;i<=n;i++)   {p[i] = i;r[i] = ;}

         while(m--)

         {

             int a,b,d;

             scanf("%d%d%d",&a,&b,&d);

             int x = finds(a);

             int y = finds(b);

             if(x==y)

             {

                 if(r[a]-r[b]!=d)  ans++;

             }

             else

             {

                 unions(a,b,x,y,d);

             }

         }

         printf("%d\n",ans);

     }

     return ;

 }