1115 timus

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <string.h>
#include <queue>
#include <map>
#include <set>
#include <cmath>
#include <sstream>
#include <stack>
#include <cassert>

#define pb push_back
#define mp make_pair
#define PI 3.1415926535897932384626433832795
#define sqr(x) (x)*(x)
#define forn(i, n) for(int i = 0; i < n; ++i)
#define ALL(x) x.begin(), x.end()
#define F first
#define S second
#define m0(x) memset(x,0,sizeof(x))
#define m1(x) memset(x,-1,sizeof(x))
#define CC(x) cout << (x) << "\n"
#define pw(x) (1ull<<(x))

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int,int> pii;
const int INF = 2147483647;
const ll LLINF = 9223372036854775807LL;

int n,m;
int a[110];
int p[110];
int b[11];
int val;

void dfs(int k) {
  if (k==m) {
    vector<int> z[11];
    for (int i=0;i<n;i++) {
      if (p[i]==-1) continue;
      z[p[i]].pb(i);
    }
    for (int i=0;i<m;i++) {
      printf("%d\n", z[i].size());
      for (int j=0;j<z[i].size();j++) printf("%d ", a[z[i][j]]);
      printf("\n");
    }
    exit(0);
  }
  if (b[k]==0) {
    dfs(k+1);
    return;
  }
  for (int i=0;i<n;i++) {
    if (p[i]!=-1) continue;
    if (a[i]<=b[k]) {
      b[k]-=a[i];
      p[i]=k;
      dfs(k);
      p[i]=-1;
      b[k]+=a[i];
    }
  }
}

int main() {
  //freopen("input.txt", "r", stdin);
  //freopen("output.txt", "w", stdout);
  scanf("%d %d", &n, &m);
  m1(p);
  for (int i=0;i<n;i++) scanf("%d", &a[i]);
  sort(a, a+n);
  reverse(a, a+n);
  for (int i=0;i<m;i++) scanf("%d", &b[i]);
  dfs(0);
  return 0;
}