#include<bits/stdc++.h>
using namespace std;
int n,m,a[2000005],p,tp,in[2000005],fa[2000005],as,sz[2000005];
vector<int>v[2000005];
priority_queue<pair<int,int> >q;
int main(){
	freopen("cuttree.in","r",stdin);
	freopen("cuttree.out","w",stdout); 
	ios::sync_with_stdio(false);
	mt19937 mt(time(0));
	cin>>n>>m;
	for(int i=0;i<n;i++) cin>>a[i];
	for(int i=0;i<n;i++){
		cin>>p;
		for(int j=1;j<=p;j++){
			cin>>tp;
			fa[tp]=i;
			in[i]++;
			sz[i]++;
		}
	}
	for(int i=0;i<n;i++){
		if(!in[i]){
			q.push({-(a[i]+a[fa[i]]+sz[fa[i]]),i});
		}
	}
	while(!q.empty()){
		int pt=q.top().second;
		q.pop();
		if(a[fa[pt]]+a[pt]+sz[fa[pt]]<=m){
			a[fa[pt]]+=a[pt];
			as++;
		}
		in[fa[pt]]--;
		if(!in[fa[pt]]) q.push({-a[fa[pt]]-a[fa[fa[pt]]]-sz[fa[pt]],fa[pt]});
	}
	cout<<as;
    return 0;
}