jd---jizhi

package jinzhi;
import java.util.Scanner;

public class Main {
	
   public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	while(sc.hasNextInt()){
		int a = sc.nextInt();
		int fenmu = a - 2;
        int fenzi = jinzhi(a);
        int gongyinshu = 1;
        int small = fenzi < fenmu ? fenzi : fenmu;
        for(int i=1;i<=small;i++){
        	if(fenzi % i == 0 && fenmu % i == 0){
        		gongyinshu = i;
        	}
        }
        System.out.println(fenzi/gongyinshu + "/" + fenmu/gongyinshu);
	}
	}
   
   public static int jinzhi(int a){
	   int sum = 0;
	   for(int i=2;i<=a-1;i++){
		   int b = a;
		 while(b != 0){
			 int yushu = b % i;
			 b = b / i;
			 sum = sum + yushu;
		 }
	 }
	   return sum;
   }
}