#include<bits/stdc++.h>
#define N 300005
using namespace std;
const int inf=1e9;
int n,rk[N],mx[N],srt[N],m;
struct node{
	int mx,id;
}p[N];
bool cmp(node p1,node p2){
	return p1.mx<p2.mx;
}
vector<int > a[N];
int h[N],to[N*5],nxt[N*5],w[N*5],cnt;
void jb(int u,int v,int W){
	w[++cnt]=W;
	to[cnt]=v;
	nxt[cnt]=h[u];
	h[u]=cnt;
}
void JB(int u,int v,int W){
	jb(u,v,W);
	jb(v,u,0);
}
int dis[N],ct[N],cur[N],k,s,t;
int dfs(int u,int fl){
	if(u==t) return fl;
	int dl=0;
	for(int &i=cur[u];i!=0;i=nxt[i]){
		int v=to[i];
		if(dis[v]+1==dis[u]&&w[i]){
			int tmp=dfs(v,min(w[i],fl-dl));
			w[i]-=tmp;
			w[i^1]+=tmp;
			dl+=tmp;
			if(dl==fl) return dl;
		}
	}
	cur[u]=h[u];
	ct[dis[u]]--;
	if(ct[dis[u]]==0) dis[s]=k+1;
	ct[++dis[u]]++;
	return dl;
}
int work(){
	for(int i=1;i<=k;i++) cur[i]=h[i];
	int res=0;
	ct[0]=k;
	while(dis[s]<=k) res+=dfs(s,inf);
	return res;
}
int id1[N],id2[N],vct[N];
int ansnxt[N],nop[N],lstp[N];
queue<int > q[N];
bool nox[N];
int main(){
	cnt=1;
	scanf("%d",&n);
	for(int i=1,j,o;i<=n;i++){
		scanf("%d",&j);
		while(j--){
			scanf("%d",&o);
			a[i].push_back(o);
			srt[++m]=o;
		}
	}
	sort(srt+1,srt+m+1);
	m=unique(srt+1,srt+m+1)-srt-1;
	for(int i=1;i<=n;i++){
		int len=a[i].size();
		for(int j=0;j<len;j++){
			a[i][j]=lower_bound(srt+1,srt+m+1,a[i][j])-srt;
			mx[i]=max(mx[i],a[i][j]);
		}
		p[i].mx=mx[i];p[i].id=i;
	}
	sort(p+1,p+n+1,cmp);
	for(int i=1;i<=n;i++) vct[p[i].mx]++;
	s=n+1,t=k=n+2;
	for(int i=1;i<=n;i++){
		JB(s,i,1);
		if(i>1&&p[i].mx==p[i-1].mx) JB(i,id2[p[i].mx],1);
		else{
			if(vct[p[i].mx]==1){
				id1[p[i].mx]=++k;
				JB(id1[p[i].mx],t,1);
			}
			else{
				id1[p[i].mx]=++k;
				id2[p[i].mx]=++k;
				JB(id2[p[i].mx],id1[p[i].mx],vct[p[i].mx]-1);
				JB(id1[p[i].mx],t,vct[p[i].mx]);
				JB(i,id2[p[i].mx],1);
			}
		}
		for(int v:a[p[i].id])
			if(v!=p[i].mx&&id1[v]) JB(i,id1[v],1);
	}
	printf("%d\n",work());
	for(int u=1;u<=n;u++){
		int toid=-1;
		for(int i=h[u];i!=0;i=nxt[i]){
			int v=to[i];
			if(v!=s&&w[i]==0) toid=v;
		}
		if(toid!=id2[p[u].mx])
			q[id1[p[u].mx]].push(u);
	}
	for(int u=1;u<=n;u++){
		int toid=-1;
		for(int i=h[u];i!=0;i=nxt[i]){
			int v=to[i];
			if(v!=s&&w[i]==0) toid=v;
		}
		if(toid==id2[p[u].mx]) continue;
		if(toid!=-1){
			ansnxt[q[toid].front()]=u;
			q[toid].pop();
		}
		lstp[p[u].mx]=u;
	}
	for(int u=1;u<=n;u++){
		int toid=-1;
		for(int i=h[u];i!=0;i=nxt[i]){
			int v=to[i];
			if(v!=s&&w[i]==0) toid=v;
		}
		if(toid==id2[p[u].mx]){
			ansnxt[u]=ansnxt[lstp[p[u].mx]];
			ansnxt[lstp[p[u].mx]]=u;
			lstp[p[u].mx]=u;
		}
	}
	for(int i=1;i<=n;i++)
		if(ansnxt[i]!=0) nox[ansnxt[i]]=1;
	for(int i=1;i<=n;i++){
		if(nox[i]) continue;
		printf("%d ",p[i].id);
		int x=ansnxt[i];
		while(x!=0){
			printf("%d ",p[x].id);
			x=ansnxt[x];
		}
	}
	return 0;
}