#include <iostream>
using namespace std;

void function(int n, int a, int b, int c)
{
    if (n == 1)
        cout << a << " " << b << endl;
    else
    {
        function(n - 1, a, c, b);
        cout << a << " " << b << endl;
        function(n - 1, c, b, a);
    }
}

int main()
{
    int n;
    cin >> n;
    function(n, 1, 2, 3);
    return 0;
}