#include using namespace std; const int inf = 1 << 30; vector lis(vector vec) { int n = vec.size(); vector dp(n, inf); vector idlist(n, -1); for(int i = 0; i < n; i++) { auto idx = distance(dp.begin(), lower_bound(dp.begin(), dp.end(), vec[i])); dp[idx] = vec[i]; idlist[i] = idx; } int cur = *max_element(idlist.begin(), idlist.end()); vector ans; for(int i = n - 1; i >= 0; i--) { if(idlist.at(i) == cur) { ans.push_back(vec[i]); --cur; } } return vector(ans.rbegin(), ans.rend()); } int main() { int n; cin >> n; vector p(n, 0), rp(n, 0); for(auto &v : p) cin >> v; for(int i = 0; i < n; i++) rp[i] = -p[n - 1 - i]; auto mn_lis = lis(p); auto mx_lis = lis(rp); for(auto &v : mx_lis) v *= -1; reverse(mx_lis.begin(), mx_lis.end()); vector res; for(int i = 0; i < (int)mn_lis.size(); i++) if(mn_lis[i] == mx_lis[i]) res.push_back(mn_lis[i]); cout << res.size() << '\n'; if(res.empty()) cout << '\n'; else for(int i = 0; i < (int)res.size(); i++) cout << res[i] << " \n"[i == (int)res.size() - 1]; return 0; }