#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(n); i++)


vector<int> LIS(vector<int> A){
    int n = A.size();
    vector<int> ord(n, -1);
    vector<int> I(n+1, 1001001001);
    rep(i,n){
        ord[i] = upper_bound(I.begin(), I.end(), A[i]) - I.begin();
        A[ord[i]] = A[i];
    }
    return ord;
}


int main(){
    int N; cin >> N;
    vector<int> A(N); rep(i,N){ cin >> A[i]; A[i]--; }

    auto lis1 = LIS(A);
    int lislen = 0;
    for(auto a : lis1) lislen = max(lislen, a); lislen += 1;

    reverse(A.begin(), A.end());
    for(auto& a : A) a *= -1;
    auto lis2 = LIS(A);
    reverse(lis2.begin(), lis2.end());
    for(auto& a : lis2) a = lislen - 1 - a;
    reverse(A.begin(), A.end());
    for(auto& a : A) a *= -1;

    vector<int> ans2(lislen, 0);
    rep(i,N) if(lis1[i] == lis2[i]) ans2[lis1[i]]++;

    int n = lis1.size();
    vector<int> ans;
    rep(i,n) if(lis1[i] == lis2[i]) if(ans2[lis2[i]] == 1) ans.push_back(A[i] + 1);
    cout << ans.size() << "\n";
    rep(i,ans.size()){
        if(i) cout << " ";
        cout << ans[i];
    }
    cout << "\n";
    return 0;
}


struct ios_do_not_sync{
    ios_do_not_sync(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }
} ios_do_not_sync_instance;