#define _CRT_SECURE_NO_WARNINGS
#pragma comment(linker, "/STACK:251700000")
#include <iostream>
#include <vector>
#include <set>
#include <string>
#include <algorithm>
#include <queue>
#include <cstdio>
#include <fstream>
#include <unordered_map>
#include <map>
#include <iterator>
#include <iomanip>
#include <stack>
#include <math.h>
#include <bitset>
#include <assert.h>
//( ° ͜ʖ͡°)╭∩╮

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef unsigned long long ull;
typedef unsigned int ui;
typedef vector<int> vi;

#define TASK "clover"
#define mp make_pair
#define X first
#define Y second
#define all(a) (a).begin(), (a).end()
#define inb push_back
#define y1 lubluAU

const ll LINF = 9e18;
const int INF = 2e9;

#ifdef _DEBUG
const int M = 2e2 + 5;
#else
const int M = (1 << 18);
#endif

struct dd
{
	int x, y, cnt, min;
	dd * l, *r;
	dd() {}
	dd(int x)
	{
		this->x = x;
		y = rand() << 15 + rand();
		cnt = min = x;
		l = r = NULL;
	}
};

typedef dd * node;

int getc(node t)
{
	if (t) return t->cnt;
	return 0;
}

int getm(node t)
{
	if (t) return t->min;
	return INF;
}

void upd(node t)
{
	if (!t) return;
	t->cnt = 1 + getc(t->l) + getc(t->r);
}

void updm(node t)
{
	if (!t) return;
	t->min = min({ t->x, getm(t->l), getm(t->r) });
}

void split(node t, int x, node &l, node &r)
{
	if (!t)
	{
		l = r = NULL;
		return;
	}
	if (x <= getc(t->l))
		split(t->l, x, l, t->l), r = t;
	else
		split(t->r, x - getc(t->l) - 1, t->r, r), l = t;
	upd(t);
	updm(t);
}

void merge(node &t, node l, node r)
{
	if (!l || !r) t = l ? l : r;
	else if (l->y > r->y)
		merge(l->r, l->r, r), t = l;
	else
		merge(r->l, l, r->l), t = r;
	upd(t);
	updm(t);
}

void ins(node &t, int x, int pos)
{
	node a, b, c, d;
	split(t, pos, a, b);
	split(b, 1, c, d);
	c = new dd(x);
	merge(b, c, d);
	merge(t, a, b);
}

void insert(node &t, int x, int l, int r)
{
	node a, b, c, d, e, f;
	split(t, l, a, b);
	split(b, r - l, c, d);
	split(d, 1, e, f);
	e = new dd(x);
	merge(a, a, e);
	merge(b, c, f);
	merge(t, a, b);
}

void got(node t, int &x)
{
	if (!t) return;
	if (!getm(t->l)) got(t->l, x);
	else
	{
		x += getc(t->l) + 1;
		if (t->x) got(t->r, x);
	}
}

int Find(node &t, int pos)
{
	node a, b;
	split(t, pos, a, b);
	int ans = 0;
	got(b, ans);
	merge(t, a, b);
	return pos + ans - 1;
}

vi ans;

void print(node t)
{
	if (!t) return;
	print(t->l);
	ans.inb(t->x);
	print(t->r);
}

int main()
{
#ifdef _DEBUG
	freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
#else
	//freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
	//freopen(TASK".in", "r", stdin), freopen(TASK".out", "w", stdout);
#endif
	/*ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);*/
	int n, m;
	scanf("%d%d", &n, &m);
	vi l(n);
	for (int i = 0; i < n; ++i)
		scanf("%d", &l[i]), l[i]--;
	node root = NULL;
	for (int i = 0; i <= max(2 * n, 2 * m); ++i) merge(root, root, new dd(0));
	for (int i = 0; i < n; ++i)
	{
		int x = Find(root, l[i]);
		if (x == l[i])
			ins(root, i + 1, l[i]);
		else
			insert(root, i + 1, l[i], x);
	}
	ans.clear();
	print(root);
	while (ans.back() == 0) ans.pop_back();
	cout << ans.size() << '\n';
	for (int i : ans) cout << i << ' ';
}