/* name: 6537
 * author: 5ab
 * created at: 2024-02-17
 */
#include <iostream>
#include <cassert>
#include <deque>
using namespace std;

#define all(x) (x).begin(), (x).end()
#define ssz(x) (int((x).size()))

auto chmax = [](auto& x, auto y) { if (x < y) x = y; };
auto chmin = [](auto& x, auto y) { if (y < x) x = y; };

using ll = long long;
const int N = 6e6, INF = 1045141919;

int a[N], s[N + 1][4], t[N][4];
// s: >= l 的第一个 x
// t: <= l 的第一个 x

signed main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int n, c[4] = {}, cnt[4];
	
	cin >> n;
	for (int i = 0; i < n; i++)
	{
		cin >> a[i];
		for (int j = 1; j <= 3; j++)
			s[i][j] = c[j];
		c[a[i]]++;
	}
	for (int j = 1; j <= 3; j++)
		s[n][j] = c[j];
	copy(c, c + 4, cnt);
	for (int i = n - 1; i >= 0; i--)
	{
		for (int j = 1; j <= 3; j++)
			t[i][j] = c[j] - 1;
		c[a[i]]--;
	}
	
	int xl = 0, yl = 0;
	for (int i = 0, j = n - 1; i < j; i++, j--)
	{
		while (i < n && a[i] != 1)
			i++;
		while (j >= 0 && a[j] != 3)
			j--;
		if (i >= j)
			break;
		xl++;
	}
	for (int i = 0, j = n - 1; i < j; i++, j--)
	{
		while (i < n && a[i] != 3)
			i++;
		while (j >= 0 && a[j] != 1)
			j--;
		if (i >= j)
			break;
		yl++;
	}
	int xyl = xl + yl;
	
	int xlm = -INF, ylm = -INF, xylm = -INF;
	for (int i = 0; i < n; i++)
	{
		chmax(xlm, s[i][2] - s[i][1]);
		chmin(xl, s[i + 1][2] - t[i][3] - xlm + cnt[3] - 1);
		chmax(ylm, s[i][2] - s[i][3]);
		chmin(yl, s[i + 1][2] - t[i][1] - ylm + cnt[1] - 1);
		chmax(xylm, s[i][2] - s[i][1] - s[i][3]);
		chmin(xyl, s[i + 1][2] - t[i][3] - t[i][1] - xylm + cnt[1] + cnt[3] - 2);
	}
	cout << min(xyl, xl + yl) << endl;
	
	xyl = xl + yl - xyl;
	int d = min(xyl, yl);
	yl -= d, xyl -= d;
	xl -= min(xyl, xl);
	
	// cerr << xl << " " << yl << endl;
	
	deque<int> sp1, sp3, tp1, tp3;
	
	c[1] = c[3] = 0;
	for (int i = 0; i < n; i++)
	{
		if (c[1] < xl && a[i] == 1)
			sp1.push_back(i);
		if (c[3] < yl && a[i] == 3)
			sp3.push_back(i);
		c[a[i]]++;
	}
	c[1] = c[3] = 0;
	for (int i = n - 1; i >= 0; i--)
	{
		if (c[1] < yl && a[i] == 1)
			tp1.push_front(i);
		if (c[3] < xl && a[i] == 3)
			tp3.push_front(i);
		c[a[i]]++;
	}
	
	auto popX = [&](int i)
	{
		cout << sp1.front() << " " << i << " " << tp3.front() << "\n";
		sp1.pop_front(), tp3.pop_front();
	};
	auto popY = [&](int i)
	{
		cout << sp3.front() << " " << i << " " << tp1.front() << "\n";
		sp3.pop_front(), tp1.pop_front();
	};
	
	for (int i = 0; i < n; i++)
		if (a[i] == 2)
		{
			if (!sp1.empty() && sp1.front() < i)
			{
				if (!sp3.empty() && sp3.front() < i)
				{
					if (tp1.front() < tp3.front())
						popY(i);
					else
						popX(i);
				}
				else
					popX(i);
			}
			else if (!sp3.empty() && sp3.front() < i)
				popY(i);
		}
	
	return 0;
}
// started coding at: 02-17 21:26:26