#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,i;
    cin>>n;
    for(i=1;i<=n;i++){
    	if(i%2==0){
    		cout<<i<<endl;
    	}
    }
	return 0;
}
/**************************************************************
	Problem: 1699
	User: linyuhang
	Language: C++
	Result: Wrong Answer
****************************************************************/