#include <iostream>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <cmath>
#include <queue>
#include <string>
#include <utility>
#include <functional>
using namespace std;
using ll = long long int;
using pii = pair<int,int>;
using pll = pair<ll,ll>;

int main(){
    int N;
    cin >> N;
    for(int i=1;i<=N;i++){
        //cout << i << ":";
        cout << (i-1)/2+1 << " " << (N+i+1)/2 << endl;
    }
}
#include <bits/stdc++.h>
using namespace std;

int main() {
	int n; cin >> n;

	for (int i = 0; i < n; i++) {
		cout << (2*i)%n + 1 << " " << (2*i+1)%n + 1 << endl;
	}
}
