#include <bits/stdc++.h>
#define pb emplace_back
#define fst first
#define scd second
#define mkp make_pair
#define mems(a, x) memset((a), (x), sizeof(a))

using namespace std;
typedef long long ll;
typedef double db;
typedef unsigned long long ull;
typedef long double ldb;
typedef pair<int, int> pii;

const int maxn = 600100;

int n, a[maxn], b[maxn][3];
vector<int> vc[maxn];

void solve() {
	scanf("%d", &n);
	for (int i = 1; i <= n; ++i) {
		scanf("%d", &a[i]);
		b[i][0] = b[i - 1][0] + (a[i] == 1);
		b[i][1] = b[i - 1][1] + (a[i] == 2);
		b[i][2] = b[i - 1][2] + (a[i] == 3);
	}
	int rab = 1e9, ra = 1e9, rb = 1e9;
	rab = ra = rb = min({b[n][0], b[n][1], b[n][2]});
	int mn1 = 1e9, mn2 = 1e9, mn3 = 1e9;
	for (int i = 0; i <= n; ++i) {
		if (i) {
			rab = min(rab, mn1 + b[n][2] - b[i][2] + b[n][0] - b[i][0] + b[i][1]);
			ra = min(ra, mn2 + b[n][2] - b[i][2] + b[i][1]);
			rb = min(rb, mn3 + b[n][0] - b[i][0] + b[i][1]);
		}
		mn1 = min(mn1, b[i][0] - b[i][1] + b[i][2]);
		mn2 = min(mn2, b[i][0] - b[i][1]);
		mn3 = min(mn3, b[i][2] - b[i][1]);
	}
	rab = min(rab, ra + rb);
	printf("%d\n", rab);
	int x = min(ra, rab);
	int y = rab - x;
	priority_queue< pii, vector<pii>, greater<pii> > pq;
	vector<int> v1, v3;
	for (int i = 1; i <= n; ++i) {
		if (a[i] == 1) {
			v1.pb(i);
		}
		if (a[i] == 3) {
			v3.pb(i);
		}
	}
	for (int i = 0; i < x; ++i) {
		vc[v1[i]].pb(v3[(int)v3.size() - x + i]);
	}
	for (int i = 0; i < y; ++i) {
		vc[v3[i]].pb(v1[(int)v1.size() - y + i]);
	}
	for (int i = 1; i <= n; ++i) {
		for (int j : vc[i]) {
			pq.emplace(j, i);
		}
		if (a[i] == 2 && pq.size()) {
			pii p = pq.top();
			pq.pop();
			printf("%d %d %d\n", p.scd - 1, i - 1, p.fst - 1);
		}
	}
}

int main() {
	int T = 1;
	// scanf("%d", &T);
	while (T--) {
		solve();
	}
	return 0;
}