#include<bits/stdc++.h>
using namespace std;
#define REP(x,y)for(ll x=0;x<ll(y);++x)
#define rep(x,y,z)for(ll x=ll(y);x<ll(z);++x)
#define PER(x,y)for(ll x=ll(y)-1;x>=0;--x)
#define per(x,y,z)for(ll x=ll(z)-1;x>=ll(y);--x)
#define all(v)v.begin(),v.end()
#define rall(v)v.rbegin(),v.rend()
#define pb emplace_back
#define fi first
#define se second
#define lb(v,k)ll(lower_bound(all(v),k)-v.begin())
#define ub(v,k)ll(upper_bound(all(v),k)-v.begin())
#define uniq(v)sort(all(v)),v.erase(unique(all(v)),v.end())
#define sz(x)ll(x.size())
#define out(x)cout<<(x)<<'\n'
#define sor(v)sort(all(v))
using ll=long long;
using P=pair<ll,ll>;
using PP=tuple<ll,ll,ll>;
using PPP=tuple<ll,ll,ll,ll>;
using vi=vector<ll>;
using vvi=vector<vi>;
using vb=vector<bool>;
using vvb=vector<vb>;
using vp=vector<P>;
using vvp=vector<vp>;
struct $_${$_$(){ios::sync_with_stdio(false);cin.tie(nullptr);}}$_$_$;
template<class T,class S>inline bool chmin(T&A,S B){if(A>B){A=B;return true;}return false;}
template<class T,class S>inline bool chmax(T&A,S B){if(A<B){A=B;return true;}return false;}
vi minlis(vi P)
{
	int N=sz(P);
	vi dp(N,N+1);
	map<int,int>prv;
	REP(i,N)
	{
		int id=lb(dp,P[i]);
		if(id)prv[P[i]]=dp[id-1];
		dp[id]=P[i];
	}
	vi lis;
	PER(i,N)if(dp[i]<N+1)
	{
		int x=dp[i];
		REP(j,i)
		{
			lis.pb(x);
			x=prv[x];
		}
		lis.pb(x);
		break;
	}
	reverse(all(lis));
	return lis;
}
vi maxlis(vi P)
{
	reverse(all(P));
	REP(i,sz(P))P[i]*=-1;
	auto Q=minlis(P);
	reverse(all(Q));
	REP(i,sz(Q))Q[i]*=-1;
	return Q;
}
void unsolve()
{
	int N;
	cin>>N;
	vi P(N);
	REP(i,N)cin>>P[i];
	auto A=minlis(P);
	auto B=maxlis(P);
	vi ans;
	REP(i,sz(A))if(A[i]==B[i])ans.pb(A[i]);
	out(sz(ans));
	REP(i,sz(ans))cout<<ans[i]<<" \n"[i==sz(ans)-1];
	if(!sz(ans))cout<<"\n";
}
int main()
{
	int T=1;
	//cin>>T;
	while(T--)
		unsolve();
}