#include <iostream>
using namespace std;
int main()
{
	int n;
	cin >> n;
	int* arr = new int[n];

	int current = ((n % 2 == 0) ? n - 2 : n - 1);
	int position = 0;
	while (current >= 0) {//Слева направо до 0
		arr[position] = current;
		current -= 2;
		position++;
	}
	position = n - 1;
	current = ((n % 2 == 0) ? n - 1 : n - 2);
	while (current >= 1) {//Справа налево до 1
		arr[position] = current;
		current -= 2;
		position--;
	}
	
	
	for (int i = 0; i < n; i++) {
		cout << i << " - " << arr[i] << endl;
	}

	delete[] arr;


}