CodeForces 659C Tanya and Toys（贪心）

题意：有无限多种商品，第i个商品值i元，现在你已经有了n个商品，你想花m元去买尽量多的不同的商品，问你应该买哪些物品。

思路：肯定是贪心排个序，选便宜的扫一遍就好了

#include <cstdio>
#include <queue>
#include <cstring>
#include <iostream>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <map>
#include <string>
#include <set>
#include <ctime>
#include <cmath>
#include <cctype>
using namespace std;
#define maxn 100000+7
#define LL long long
int cas=1,T;
LL a[maxn];
vector<int>ans;
int main()
{
	int n,m;
	scanf("%d%d",&n,&m);
	for (int i = 1;i<=n;i++)
		scanf("%d",&a[i]);
	sort(a+1,a+1+n);
	for (int i = 1,j=1;;i++)
	{
		if (j<=n && i==a[j])
			j++;
		else if (m<i)
			break;
		else
			m-=i,ans.push_back(i);
	}
	cout << ans.size()<<endl;
	for (int i = 0;i<ans.size();i++)
		cout << ans[i] << " ";
	cout << endl;

	//freopen("in","r",stdin);
	//scanf("%d",&T);
	//printf("time=%.3lf",(double)clock()/CLOCKS_PER_SEC);
	return 0;
}

Description

In Berland recently a new collection of toys went on sale. This collection consists of 10⁹ types of toys, numbered with integers from 1to 10⁹. A toy from the new collection of the i-th type costs i bourles.

Tania has managed to collect n different types of toys a₁, a₂, ..., a_n from the new collection. Today is Tanya's birthday, and her mother decided to spend no more than m bourles on the gift to the daughter. Tanya will choose several different types of toys from the new collection as a gift. Of course, she does not want to get a type of toy which she already has.

Tanya wants to have as many distinct types of toys in her collection as possible as the result. The new collection is too diverse, and Tanya is too little, so she asks you to help her in this.

Input

The first line contains two integers n (1 ≤ n ≤ 100 000) and m (1 ≤ m ≤ 10⁹) — the number of types of toys that Tanya already has and the number of bourles that her mom is willing to spend on buying new toys.

The next line contains n distinct integers a₁, a₂, ..., a_n (1 ≤ a_i ≤ 10⁹) — the types of toys that Tanya already has.

Output

In the first line print a single integer k — the number of different types of toys that Tanya should choose so that the number of different types of toys in her collection is maximum possible. Of course, the total cost of the selected toys should not exceed m.

In the second line print k distinct space-separated integers t₁, t₂, ..., t_k (1 ≤ t_i ≤ 10⁹) — the types of toys that Tanya should choose.

If there are multiple answers, you may print any of them. Values of t_i can be printed in any order.

Sample Input

Input

3 7
1 3 4

Output

2
2 5 

Input

4 14
4 6 12 8

Output

4
7 2 3 1