import java.util.ArrayList;
import java.util.Scanner;
class Main{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
sc.nextLine();
ArrayList<Integer> list = new ArrayList<>();
while(n-->0)
list.add(sc.nextInt());
for (int i = 0; i < list.size(); i++) {
int t = list.get(i);
if(t==0){
list.remove(i);
i--;
}
}
System.out.println(list.size());
String s = "";
for (int i = 0; i < list.size(); i++) {
s+=list.get(i)+" ";
}
System.out.println(s.trim());
}
}
