int n,m;

int fa[200005];

int sum[200005];

int findFa(int x){

    if(fa[x]==x){

        return fa[x];

    }

    int t=fa[x];

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

    sum[x]+=sum[t];

    return fa[x];

}

int main(){

    while(scanf("%d%d",&n,&m)!=EOF){

        rep(i,0,n){

            fa[i]=i;

            sum[i]=0;

        }

        int ans=0;

        while(m--){

            int A,B,S;

            scanf("%d%d%d",&A,&B,&S);

            int fA=findFa(A-1);

            int fB=findFa(B);

            if(fA!=fB){

                fa[fB]=fA;

                sum[fB]+=(sum[A-1]+S-sum[B]);

            }else{

                if(sum[A-1]+S!=sum[B]){

                    ++ans;

                }

            }

        }

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

    }

    return 0;

}