#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using db = double;
using vi = vector<int>;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
#define debug(x) cout << #x <<"	"<< x <<endl
const int inf = 0x3f3f3f3f;
const db eps = 1e-8;
const int mod = 1e9+7;
ll qpow(ll a, ll b){
    ll ret = 1;
    while(b){
        if(b&1)ret = ret*a%mod;
        a = a*a%mod;
        b>>=1;
    }
    return ret;
}
const int maxn = 1<<10;
int n;
int a[maxn], b[maxn];
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
	cin >> n;
	for(int i=1; i<=n; ++i){
		a[i] = (2*i)%n+1;
		b[i] = (2*i+1)%n+1;
	}
	for(int i=1; i<=n; ++i)cout << a[i] <<" " << b[i] <<"\n";
    return 0;
}


//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<n; ++i)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
using namespace std;
using ll = int64_t;
using ld = long double;
using P = pair<int, int>;
using vs = vector<string>;
using vi = vector<int>;
using vvi = vector<vi>;
template<class T> using PQ = priority_queue<T>;
template<class T> using PQG = priority_queue<T, vector<T>, greater<T> >;
const int INF = 0xccccccc;
const ll LINF = 0xcccccccccccccccLL;
template<typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {return a < b && (a = b, true);}
template<typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {return a > b && (a = b, true);}
template<typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) { return is >> p.first >> p.second;}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << p.first << ' ' << p.second;}



//head



int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n;
	cin >> n;
	int now = 1;
	auto get = [&]() {
		if(now == n) return now = 1;
		return ++now;
	};
	//cout << n << endl;
	rep(i, n) {
		cout << get() << ' ' << get() << '\n';
	}
}