#include <iostream>
using namespace std;
int main () {
int a, b;
cin >> a;
for (b = 1; b <= a; b++ ){
if ( b % 2 == 0){
cout << b << endl;
}
#include <iostream>
using namespace std;
int main () {
int a, b;
cin >> a;
for (b = 1; b <= a; b++ ){
if ( b % 2 == 0){
cout << b << endl;
}
}
}