UVA11100 The Trip, 2007

//Serene
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<cmath>
#include<vector>
using namespace std;
const int maxn=1e4+10,INF=0x3f3f3f3f;
int T,n,a[maxn],now,f;

int aa,ff;char cc;
int read() {
	aa=0;cc=getchar();ff=1;
	while(cc<‘0‘||cc>‘9‘) {
		if(cc==‘-‘) ff=-1;
		cc=getchar();
	}
	while(cc>=‘0‘&&cc<=‘9‘) aa=aa*10+cc-‘0‘,cc=getchar();
	return aa*ff;
}

int main() {
	n=read();
	while(n) {
		 now=0;f=0;
		for(int i=1;i<=n;++i) a[i]=read();
		sort(a+1,a+n+1);
		for(int i=1;i<=n;++i) {
			if(a[i]==a[i-1]) now++;
			else now=1;
			f=max(f,now);
		}
		printf("%d\n",f);
		for(int i=1;i<=f;++i) {
			printf("%d",a[i]);
			for(int j=i+f;j<=n;j+=f) printf(" %d",a[j]);
			printf("\n");
		}
		n=read();
	}
	return 0;
}