1115

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <map>
#include <set>
#include <vector>
#include <algorithm>
#include <queue>
#include <bitset>
#include <stack>
#include <iostream>
#include <fstream>
#include <cmath>
#include <ctime>

#define sqr(a) ((a)*(a))
#define odd(a) ((a)&1)
#define foru(i,n) for (int i=0;i<(n);i++)
#define ford(i,n) for (int i=(n)-1;i>=0;i--)
#define forab(i,l,r) for (int i=(l);i<=(r);i++)
#define forabd(i,r,l) for (int i=(r);i>=(l);i--)
#define pb push_back
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define sz(__X) (int)__X.size()
#define pii pair<int,int>

const double eps=1e-19;
const double PI=acos(-1.0);
const int INF=1000*1000*1000+7;
const int MAXN = 100005;

using namespace std;

int n,m;
int a[MAXN];
int b[MAXN];
vector<int> ans[15];
vector<int> pr[10000];
bool was[105];

void rec(int x)
{
    if ( x == m)
    {
        for (int i=0; i<m; i++)
        {
            printf("%d\n", sz(ans[i]));
            for (int j=0;j<sz(ans[i]); j++)
                printf("%d ", ans[i][j]);
            printf("\n");
        }
        exit(0);
    }
    int u = b[x];
    for (int j=0; j<sz(pr[u]); j++)
    {
        if ( !was[pr[u][j]] )
        {
            int v = pr[u][j];
            ans[x].push_back(a[v]);
            was[v]=true;
            b[x] -= a[v];
            if ( b[x] == 0)
                rec(x+1);
                else rec(x);
            b[x]+=a[v];
            ans[x].pop_back();
            was[v]=false;
        }
    }
}

int main()
{
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    scanf("%d %d", &n, &m);
    pr[0].push_back(-1);
    for (int i=0; i<n; i++)
    {
        scanf("%d", &a[i]);
    }
    srand(time(NULL));
    sort(a, a+n);
    for (int i=n; i>=0; i--)
    {
        for (int j=9900; j>=0; j--)
        {
            if ( !pr[j].empty() )
                pr[j+a[i]].push_back(i);
        }
    }
    for (int i=0; i<m; i++)
        scanf("%d", &b[i]);
    rec(0);
    return 0;
}