Description

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<queue>
using namespace std;

const int MAXN = 520;
const int MAXM = 100000;
const int INF = 0x3f3f3f3f;

struct Edge
{
	int from, to, cap, next, oricap;
};


Edge edge[MAXM];
int head[MAXN];
int stu[405][405];
int level[MAXN];
int src, des, cnt;


void addedge( int from, int to, int cap )
{
	edge[cnt].from = from;
	edge[cnt].to = to;
	edge[cnt].cap = cap;
	edge[cnt].oricap = cap;
	edge[cnt].next = head[from];
	head[from] = cnt++;

	swap( from, to );

	edge[cnt].from = from;
	edge[cnt].to = to;
	edge[cnt].cap = 0;
	edge[cnt].oricap = 0;
	edge[cnt].next = head[from];
	head[from] = cnt++;
}

int bfs( )
{
	memset( level, -1, sizeof level );
	queue<int> q;
	while (!q.empty( ))
		q.pop( );

	level[src] = 0;
	q.push( src );

	while (!q.empty( ))
	{
		int u = q.front( );
		q.pop( );

		for (int i = head[u]; i != -1; i = edge[i].next)
		{
			int v = edge[i].to;
			if (edge[i].cap > 0 && level[v] == -1)
			{
				level[v] = level[u] + 1;
				q.push( v );
			}
		}
	}
	return level[des] != -1;
}

int dfs( int u, int f )
{
	if (u == des)	return f;
	int tem;
	for (int i = head[u]; i != -1; i = edge[i].next)
	{
		int v = edge[i].to;
		if (edge[i].cap > 0 && level[v] == level[u] + 1)
		{
			tem = dfs( v, min( f, edge[i].cap ) );
			if (tem > 0)
			{
				edge[i].cap -= tem;
				edge[i ^ 1].cap += tem;
				return tem;
			}
		}
	}
	level[u] = -1;
	return 0;
}

int Dinic( )
{
	int ans = 0, tem;
	while (bfs( ))
	{
		while ((tem = dfs( src, INF )) > 0)
		{
			ans += tem;
		}
	}
	return ans;
}

int main( )
{
	int n, m;
	src = 0; des = 510;
	string str;
	while (cin >> n >> m)
	{
		memset( head, -1, sizeof head );
		cnt = 0;
		for (int i = 1; i <= n; i++)
		{
			addedge( src, i, 1 );
			int unum;
			cin >> unum;
			for (int j = 1; j <= unum; j++)
			{
				int u;
				cin >> u;
				addedge( i, u + 200, 1 );
			}
		}

		for (int i = 1; i <= m; i++)
		{
			addedge( i + 200, des, 2 );
			stu[i + 200][0] = 0;
		}
		if (Dinic( ) < m * 2)
		{
			cout << "NO" << endl;
			continue;
		}
		for (int i = 1; i <= n; i++)
		{
			for (int j = head[i]; j != -1; j = edge[j].next)
			{
				if (edge[j].to != src&&edge[j].oricap>edge[j].cap)
				{
					stu[edge[j].to][++stu[edge[j].to][0]] = i;
				}
			}
		}

		cout << "YES" << endl;
		for (int i = 1; i <= m; i++)
		{
			cout << stu[i + 200][0] << " ";
			for (int j = 1; j < stu[i + 200][0]; j++)
			{
				cout << stu[i + 200][j] << " ";
			}
			cout << stu[i + 200][stu[i + 200][0]] << endl;
		}
	}

	return 0;
}