import java.util.Scanner;
public class P1014 {

	public static void main(String[] args) {
		Scanner in=new Scanner(System.in); 
		int a=in.nextInt();
		int temp=a;
		int i;		
		for(i=1;i<temp;i++) {
			temp=temp-i;
		}
		System.out.println(temp+"/"+(i-temp+1));
	}
}