Problem: As meticulous Gerald sets the table and caring Alexander sends the postcards, Sergey makes snowmen. Each showman should consist of three snowballs: a big one, a medium one and a small one. Sergey's twins help him: they've already made n snowballs with radii equal to r1, r2, ..., rn. To make a snowman, one needs any three snowballs whose radii are pairwise different. For example, the balls with radii 1, 2 and 3 can be used to make a snowman but 2, 2, 3 or 2, 2, 2 cannot. Help Sergey and his twins to determine what maximum number of snowmen they can make from those snowballs.

Input

The first line contains integer n (1 ≤ n ≤ 105) — the number of snowballs. The next line contains n integers — the balls' radii r1, r2, ..., rn (1 ≤ ri ≤ 109). The balls' radii can coincide.

Output

Print on the first line a single number k — the maximum number of the snowmen. Next k lines should contain the snowmen's descriptions. The description of each snowman should consist of three space-separated numbers — the big ball's radius, the medium ball's radius and the small ball's radius. It is allowed to print the snowmen in any order. If there are several solutions, print any of them.

Examples

Input

7
1 2 3 4 5 6 7


Output

2
3 2 1
6 5 4


Input

3
2 2 3


Output

0

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;
public class C {
	
	static final int MAXN = 200001;
	
	class Ball implements Comparable<Ball> {
		public int v, c;
		public Ball(int v, int c) {
			this.v = v;
			this.c = c;
		}
		public int compareTo(Ball other) {
			if (other.c != this.c) return other.c - this.c;
			return other.v - this.v;
		}
	}
	
	final public void solve() throws IOException {
		int n = nextInt();
		int[] a = new int[n];
		for (int i = 0; i < n; i++)
			a[i] = nextInt();
		Arrays.sort(a);
		TreeSet<Ball> s = new TreeSet<Ball>();
		int pre = 0;
		for (int i = 1; i < n; i++)
			if (a[i] != a[pre]) {
				//System.out.println(s.size());
				s.add(new Ball(a[pre], i - pre));
				pre = i;
			}
		s.add(new Ball(a[pre], n - pre));
		int ans = 0;
		int[][] out = new int[MAXN][3];
		while (s.size() >= 3) {
			Ball x1 = s.pollFirst();
			Ball x2 = s.pollFirst();
			Ball x3 = s.pollFirst();
			
			out[ans][0] = x1.v;
			out[ans][1] = x2.v;
			out[ans][2] = x3.v;
			Arrays.sort(out[ans], 0, 3);
			int tmp = out[ans][0];
			out[ans][0] = out[ans][2];
			out[ans][2] = tmp;
			ans++;
			
			if (x1.c > 1) s.add(new Ball(x1.v, x1.c - 1));
			if (x2.c > 1) s.add(new Ball(x2.v, x2.c - 1));
			if (x3.c > 1) s.add(new Ball(x3.v, x3.c - 1));
		}
		System.out.println(ans);
		for (int i = 0; i < ans; i++)
			System.out.println(out[i][0] + " " + out[i][1] + " " + out[i][2]);
	}

	public static void main(String[] args) throws FileNotFoundException {
		new C().run();
	}

	BufferedReader reader;
	StringTokenizer tokenizer;
	PrintWriter writer;

	final public void run() {
		try {
			long tbegin = System.currentTimeMillis();
			reader = new BufferedReader(new InputStreamReader(System.in));
			//reader = new BufferedReader(new InputStreamReader(new FileInputStream("fselect.inp")));
			tokenizer = null;
			writer = new PrintWriter(new OutputStreamWriter(System.out));
			//writer = new PrintWriter(new FileOutputStream("fselect.out"));
			solve();
			//reader.close();
			//System.out.println(System.currentTimeMillis() - tbegin + "ms...");
			writer.close();
		} catch (Exception e) {
			e.printStackTrace();
			System.exit(1);
		}
	}

	final int nextInt() throws IOException {
		return Integer.parseInt(nextToken());
	}

	final long nextLong() throws IOException {
		return Long.parseLong(nextToken());
	}

	final double nextDouble() throws IOException {
		return Double.parseDouble(nextToken());
	}

	final String nextToken() throws IOException {
		while (tokenizer == null || !tokenizer.hasMoreTokens()) {
			tokenizer = new StringTokenizer(reader.readLine());
		}
		return tokenizer.nextToken();
	}
}