#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]<<" ";
}
}
}
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