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

class OutParser {
private:
    FILE *fout;
    char *buff;
    int sp;

    void write_ch(char ch) {
        if (sp == 50000) {
            fwrite(buff, 1, 50000, fout);
            sp = 0;
            buff[sp++] = ch;
        } else {
            buff[sp++] = ch;
        }
    }


public:
    OutParser(const char* name) {
        fout = fopen(name, "w");
        buff = new char[50000]();
        sp = 0;
    }
    ~OutParser() {
        fwrite(buff, 1, sp, fout);
        fclose(fout);
    }

    OutParser& operator << (int vu32) {
        if (vu32 <= 9) {
            write_ch(vu32 + '0');
        } else {
            (*this) << (vu32 / 10);
            write_ch(vu32 % 10 + '0');
        }
        return *this;
    }

    OutParser& operator << (long long vu64) {
        if (vu64 <= 9) {
            write_ch(vu64 + '0');
        } else {
            (*this) << (vu64 / 10);
            write_ch(vu64 % 10 + '0');
        }
        return *this;
    }

    OutParser& operator << (char ch) {
        write_ch(ch);
        return *this;
    }
    OutParser& operator << (const char *ch) {
        while (*ch) {
            write_ch(*ch);
            ++ch;
        }
        return *this;
    }
};

int n;
int main()
{

    freopen("tije.in", "r", stdin);
    OutParser fout("tije.out");

    scanf("%d", &n);
    for(int i = n - 1; i >= 1 ; --i){
        for(int j = n; j >= 1 ; --j){
            int k = 1;
            for(k; k + 4 <= i ; k += 4){
                fout << j << " " << j + 1 << "\n";
                fout << j << " " << j + 1 << "\n";
                fout << j << " " << j + 1 << "\n";
                fout << j << " " << j + 1 << "\n";
            }
            for(k; k <= i ; ++k)
                fout << j << " " << j + 1 << "\n";
        }

        for(int k = 1; k <= i ; ++k)
            fout << n + 1 << " " << 1 << "\n";
    }


    return 0;
}