import java.util.Scanner;

class Main {
    public static long gcd(long x, long y) {
        long r;
        if (y < x) {
            r = x;
            x = y;
            y = r;
        }
        while (y > 0) {
            r = x % y;
            x = y;
            y = r;
        }
        return x;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextInt();
        sc.close();
        System.out.print(gcd(N, (N - 1) * N / 2));
    }
}