#include <bits/stdc++.h>

using namespace std;
using ll = long long;
const ll inf=10000000000;
const ll N=1000,M=1e6;
ll n,m,S,T,h[N],ne[M],e[M],f[M],d[M],cur[M],idx;

void add(ll u,ll v,ll w){
    e[idx]=v,ne[idx]=h[u],f[idx]=w,h[u]=idx++;
    e[idx]=u,ne[idx]=h[v],f[idx]=0,h[v]=idx++;
}

bool bfs(){
    memset(d,-1,sizeof d);
    d[S]=0;
    cur[S]=h[S];
    queue <ll> q;
    q.push(S);
    while(q.size()){
        ll t=q.front();q.pop();
        for(int i=h[t];i!=-1;i=ne[i]){
            int ver=e[i];
            if(d[ver]==-1 && f[i]){
                d[ver]=d[t]+1;
                cur[ver]=h[ver];
                if(ver==T) return true;
                q.push(ver);
            }
        }
    }
    return false;
}

ll find(ll u,ll limit){
    if(u==T) return limit;
    ll flow=0;
    for(int i=cur[u];i!=-1 && flow<limit;i=ne[i]){
        cur[u]=i;
        int ver=e[i];
        if(d[ver]==d[u]+1 && f[i]){
            ll t=find(ver,min(f[i],limit-flow));
            if(t==0) d[ver]=-1;
            f[i]-=t;f[i^1]+=t;flow+=t;
        }
    }
    return flow;
}

ll dinic(){
    ll ans=0,flow;
    while(bfs()) while(flow=find(S,inf)) ans+=flow;
    return ans;
}

int main(){
    cin>>n>>m;
    memset(h,-1,sizeof h);
    S=0,T=n+m+1;
    ll sum=0;
    for(ll i=1;i<=n;i++){
        ll x;
        cin>>x;
        sum+=x;
        add(S,i,x);
    }
    for(ll i=1;i<=m;i++){
        ll x;
        cin>>x;
        add(i+n,T,x);
    }
    for(ll i=1;i<=n;i++){
        for(ll j=1;j<=m;j++){
            add(i,n+j,1);
        }
    }
    ll final=dinic();
    vector <vector <ll>> ans(n+1);
    if(sum==final){
        cout<<1<<endl;
        for(int i=0;i<idx;i+=2){
            if(e[i]>n && e[i^1]<=n && !f[i]){
                ans[e[i^1]].push_back(e[i]-n);
            }
        }
        for(ll i=1;i<=n;i++){
            for(auto t:ans[i]){
                cout<<t<<' ';
            }
            cout<<endl;
        }
    }
    else cout<<0<<endl;
    return 0;
}