不喜勿喷

#include <bits/stdc++.h>
using namespace std;
int main(){
	int n;
    cin >> n;
    for (int i=1;i<=n;i++){
        if (i % 2 != 0) cout << i+1 << " ";
        else cout << i-1 << " ";
    }
	return 0;
}

不喜勿喷哈