uva11100

#include <iostream>
#include <istream>
#include <sstream>
#include <vector>
#include <stack>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
#include <algorithm>
#include <numeric>
#include <chrono>
#include <ctime>
#include <cmath>
#include <cctype>
#include <string>
#include <cstdio>
#include <iomanip>


#include <thread>
#include <mutex>
#include <condition_variable>
#include <functional>
#include <iterator>
using namespace std;
const int maxn = 10007;
int n,m;
vector<int> ans[maxn];
map<int, int> mmp;

int main()
{
    
	while (cin >> n && n) {
    
		int input,num = 0;
		mmp.clear();
		for (int i = 0; i < n; i++) {
    
			cin >> input;
			mmp[input]++;
			if (mmp[num] < mmp[input]) {
    
				num = input;
			}
		}
		m = mmp[num];
		int first = 0;
		for (int i = 0; i < m; i++) {
    
			ans[i].clear();
		}

		for (auto it = mmp.begin(); it != mmp.end(); it++) {
    
			if (it->first == num) {
    
				for (int i = 0; i < m; i++)ans[i].push_back(num);
				continue;
			}
			int cnt = it->second;
			for (int i = 0; i < cnt; i++) {
    
				ans[first].push_back(it->first);
				first = (first + 1) % m;
			}
		}
		cout << m << endl;
		for (int i = 0; i < m; i++) {
    
			for (int j = 0; j < ans[i].size(); j++) {
    
				if (j)cout << " ";
				cout << ans[i][j];
			}
			cout << endl;
		}
	}
	return 0;
}