#include <bits/stdc++.h>
#include <time.h>
using namespace std;

#define sz(x) ((int)(x).size())
#define pb push_back
#define vt vector
#define arr array
#define fi first
#define se second
#define ends "\n"
#define sp ' '
#define fun function
#define rall(x) (x).rbegin(), (x).rend()
#define all(x) (x).begin(), (x).end()

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

const long long MOD=1e9+7; 

void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) { cerr << to_string(h); if(sizeof...(t)) cerr << ", "; DBG(t...); }
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)

const int LB = -2e9, RB = 2e9;

int main(void){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr); cerr.tie(nullptr);
 	
    int N, M; cin >> N >> M;
    vector<int> A(N); for(auto &a : A) cin >> a;

    queue<int> Q;
    //set<int> st;
    map<int, int> mp;

    for(auto &a : A){
    	Q.push(a);
    	mp[a] = 0;
    }

    vector<int> ans;
    int cnt = 0;
    ll sum = 0;

    while(cnt != M && !Q.empty()){
    	auto T = Q.front(); Q.pop();
    	if(T - 1 >= LB){
    		if(!mp.count(T - 1)){
    			mp[T - 1] = mp[T] + 1;
    			sum += (ll)mp[T-1];
    			Q.push({T - 1});
    			ans.pb(T - 1);
    			++cnt;
    		}
    	}

    	if(T - 1 <= RB && cnt != M){
    		if(!mp.count(T + 1)){
    			mp[T + 1] = mp[T] + 1;
    			sum += (ll)mp[T + 1];
    			Q.push({T + 1});
    			ans.pb(T + 1);
    			++cnt;
    		}
    	}
    	// dbg(T, sum);
    }

    cout << sum << ends;
    for(auto &a : ans)
    	cout << a << sp;
    cout << ends;
 	
}