#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;
	} 
}
/**************************************************************
	Problem: 1699
	User: linzihang
	Language: C++
	Result: Memory Limit Exceed
****************************************************************/