#include <bits/stdc++.h>
using namespace std;

int main(){ 
	int a[1000]={0},n,i,r[1000]={0},k,p,j,x[1000][100]={0};
	cin>>n;
	for(i=1;i<=n;i++){
		cin>>a[i];
	}
	
	k=0; 
	for(i=1;i<=n;i++){ 
		p=-1; 
		for(j=1;j<=k;j++){
			if(r[j]>=a[i]){
				if(p==-1){
					p = j;
				} else if(r[j]<r[p]){
					p=j;
				}
			} 
		}  
		if(p==-1){
			k++;
			r[k]=a[i];
			x[k][1]=a[i];
		}else{
			r[p]=a[i];
			for(int yy=1;yy<=n;yy++){
				if(x[p][yy]==0){
					x[p][yy]=a[i];
					break;
				}
			}
		}
	} 
	
	cout<<k<<endl;
	for(int i=1;i<=k;i++){
		cout<<i<<":";
		for(int j=1;x[i][j]!=0;j++){
			cout<<x[i][j]<<" ";
		}
		cout<<endl;
	}
}

/**************************************************************
	Problem: 1375
	User: admin
	Language: C++
	Result: Accepted
	Time:12 ms
	Memory:2348 kb
****************************************************************/