#include <cstdio>

#include <cstring>

#include <queue>

#include <set>

#include <map>

#include <stack>

#include <cstdlib>

#include <algorithm>

#include <vector>

#include <cmath>

using namespace std;

const int N=2e5+;

int n,m,fa[N],sum[N];

int find(int x)

{

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

    int t=fa[x];

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

    sum[x]+=sum[t];

    return fa[x];

}

int main()

{

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

    {

        for(int i=; i<=n; ++i)fa[i]=i,sum[i]=;

        int ans=;

        while(m--)

        {

            int u,v,w;

            scanf("%d%d%d",&u,&v,&w);

            int x=find(u),y=find(v);

            if(x==y)

            {

                if(sum[v]-sum[u]!=w)++ans;

            }

            else if(x>y)

            {

                sum[x]=sum[v]-sum[u]-w;

                fa[x]=y;

            }

            else

            {

                sum[y]=sum[u]-sum[v]+w;

                fa[y]=x;

            }

        }

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

    }

    return ;

}