#include <bits/stdc++.h>

using namespace std;

ifstream in("tije.in");
ofstream out("tije.out");

string ans;

inline void MOVE( const int &a, const int &b ) {
    ans += std::to_string(a) + " " + std::to_string(b) + "\n";
}

int main(){
    int N;
    in >> N;
    for( int i = N - 1; i; --i ) {
        for( int j = N; j; -- j )
            for( int k = i; k; -- k) MOVE(j,j+1);
        for( int j = i; j; --j ) MOVE(N+1,1);
    }
    out << ans;
    return 0;
}