#include <bits/stdc++.h>
using namespace std;

int main() {
    int n;
    cin>>n;
    int *x = new int [n];
    for ( int i=0; i<n; i++ ) {
        cin>>x[i];
    }
    int num=0;
    for ( int i=0; i<n; i++ ) {
        if (x[i]>0 ) {
            num++ ; 
        }
    } 
    if (num == 0) {
        cout<<"NO";
    }
    if ( num != 0 ) {
    	cout<<num;
    }

    cout<<endl;
    for ( int i=0; i<n; i++ ) {
        cin>>x[i];
    }
    for ( int i=0; i<n; i++ ) {
        if ( x[i]>0 ) {
            cout<<x[i]<<" ";
        }       
    }
}