tj

#include<bits/stdc++.h>
using namespace std;

int main()
{
    int a;
    cin>>a;
    for(int i = 1;i<=a;i++)
        {
            if(i%2==1)
            {
                cout<<i+1;
            }else{
                cout<<i-1;
            }
            cout<<" ";
        }
}