#include<bits/stdc++.h>

using namespace std;

int main()

{

int n,i=1;

cin>>n;

if(n%2==0)

{

for(i=2;i<=n;i=i+2)

{

cout<<i<<" ";

}

}

else

{

i++;

for(i=2;i<=n;i=i+2)

{

cout<<i<<" ";

}

}

return 0;

}