#include < iostream >
#include < vector >
#include < cmath >
using namespace std;
using ll = long long;
using ld = long double;
signed main() {
ll k;
cin >> k;
vector d(k), e(k,0);
ll cnt = 0;
for(ll &i: d){
cin >> i;
if(i != 0){
e[cnt] = i;
cnt++;
}
}
cout << cnt << "n";
for(ll i:e)
cout << i << " ";
}