#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<queue>
#include<map>
#include<vector>
#include<math.h>
using namespace std;
#define ll long long
#define INF 0x3f3f3f3f
#define maxn 10005
#define N 200005
int fa[N],sum[N];
int Find(int x)
{
    if(x!=fa[x])
    {
        int po=fa[x];
        fa[x]=Find(fa[x]);
        sum[x]+=sum[po];
    }
    return fa[x];
}
int main()
{
    int n,m,e,f,g;
    while(scanf("%d%d",&n,&m)!=EOF)
    {
        for(int i=0; i<=n; i++)
        {
            fa[i]=i;
            sum[i]=0;
        }
        int ans=0;
        while(m--)
        {
            scanf("%d%d%d",&e,&f,&g);
            e--;
            int x=Find(e);//查找这个点的父节点
            int y=Find(f);if(x==y)
            {
                if(sum[f]-sum[e]!=g)
                    ans++;
            }
            else if(x<y)
            {
                fa[y]=x;
                sum[y]=g+sum[e]-sum[f];
            }
            else
            {
                fa[x]=y;
                sum[x]=sum[f]-g-sum[e];
            }
        }
        printf("%d\n",ans);
    }
    return 0;
}