#include <cstdio>

 #include <iostream>

 #define N 1000001

 int n, m, ans;

 int f[N], d[N];

 inline int read()

 {

     int x = , f = ;

     char ch = getchar();

     for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -;

     for(; isdigit(ch); ch = getchar()) x = (x << ) + (x << ) + ch - '';

     return x * f;

 }

 inline int find(int x)

 {

     if(x ^ f[x])

     {

         int fx = f[x];

         f[x] = find(f[x]);

         d[x] += d[fx];

     }

     return f[x];

 }

 int main()

 {

     int i, x, y, z, fx, fy;

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

     {

         ans = ;

         for(i = ; i <= n; i++) f[i] = i, d[i] = ;

         for(i = ; i <= m; i++)

         {

             x = read() - ;

             y = read();

             z = read();

             fx = find(x);

             fy = find(y);

             if(fx == fy)

             {

                 if((d[x] - d[y]) ^ z) ans++;

             }

             else

             {

                 d[fx] = d[y] - d[x] + z;

                 f[fx] = fy;

             }

         }

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

     }

     return ;

 }