import java.io.*; import java.util.*;
public class gift{
static class FastReader
{
BufferedReader br;
StringTokenizer st;
public FastReader()
{
br = new BufferedReader(new
InputStreamReader(System.in));
}
String next()
{
while (st == null || !st.hasMoreElements())
{
try
{
st = new StringTokenizer(br.readLine());
}
catch (IOException e)
{
e.printStackTrace();
}
}
return st.nextToken();
}
int nextInt()
{
return Integer.parseInt(next());
}
}
public static class Pair implements Comparable<Pair>{
int ind; long val;
public Pair(int a, long b){
this.ind=a; this.val=b;
}
public int compareTo(Pair other){
if(this.val<other.val)return -1;
if(this.val>other.val)return 1;
if(this.ind<other.ind)return -1;
return 1;
}
}
static int MOD=998244353;
static int[] rk, p,siz;
public static void main(String[] args){
FastReader br=new FastReader();
int N=br.nextInt(); int K=br.nextInt();
long[] a=new long[N];
long sum=0; long max=0;
for (int i = 0; i < N; i++) {
a[i]=br.nextInt(); sum+=a[i]; max=Math.max(max,a[i]);
}
if(sum%K>0 || sum/K < max){
System.out.println("-1");return;
}
//A number is bottle neck if a[i]
long cur=sum/K;
PriorityQueue<Pair> pq=new PriorityQueue<>();
//Tracks K+1 elements
long d;StringBuilder ans=new StringBuilder();
int op=0;
for (int j = 0; j < K; j++) {
pq=new PriorityQueue<>();
for (int i = 0; i < N; i++) {
if(pq.size()<=K){
pq.add(new Pair(i,a[i]));
}else if(pq.peek().val < a[i]){
pq.poll(); pq.add(new Pair(i,a[i]));
}
}
d=cur-pq.poll().val;
if(d==0)continue;
op++;
ans.append(d+" ");
for (Pair p: pq) {
ans.append((p.ind+1)+" ");
a[p.ind]-=d;
}
ans.append("\n");
cur-=d;
}
//Now K of them are "bottlenecks"
ans.append("\n");
boolean val=false;
for (int i = 0; i < N; i++) {
if(a[i]>0){
if(!val){
val=true;
op++;
ans.append(a[i]+" ");
}
ans.append((i+1)+" ");
}
}
System.out.println(op);
System.out.println(ans.toString());
}
public static int find(int x, int[] p){
if(p[x]==x)return x;
int ans=find(p[x],p); p[x]=ans; return ans;
}
public static void merge(int a, int b) {
if(rk[a]<rk[b]) {
p[a]=b; siz[b]+=siz[a];
}else if(rk[a]==rk[b]) {
p[a]=b; rk[b]++;siz[b]+=siz[a];
}else {
p[b]=a; siz[a]+=siz[b];
}
}
public static long pow(int b, int e){
if(e==0)return 1; if(e==1)return b;
long x=pow(b,e/2); x*=x; x%=MOD; x*=pow(b,e%2); return x%MOD;
}
public static void dfs(ArrayList<Integer>[] arl, int cur){
for (int i : arl[cur]) {
}
}
}
//Debugging:
//Are you sure your algorithm is correct?
//Bounds: long
//Special cases: n=0,1?
//Make sure you remove your debugging code before you submit!
Compilation message
nicegift.java:2: error: class gift is public, should be declared in a file named gift.java
public class gift{
^
1 error
