#include<iostream>
#include<cmath>
using namespace std;
int main()
{
    int n;
    cin >> n;
    int num = 1,x = 1,y = 1;
    for(int j = 0;j < n-1;j++){
        if(x == num){
                x = 0;
                num++;
        }
        x++;y--;
        if(y == 0){y = num;}
    }
    cout << x << '/' << y << endl;
}