In the late XIXth century the German mathematician George Cantor argued that the set of positive fractions Q+ is equipotent to the set of positive integers N, meaning that they are both infinite, but of the same class. To justify this, he exhibited a mapping from N to Q+ that is onto. This mapping is just traversal of the N × N plane that covers all the pairs: The first fractions in the Cantor mapping are: 1, 21, 12, 31, 2, 13,... Write a program that finds the i-th Cantor fraction following the mapping outlined above. Input The inputs consists of several lines with a positive integer number i each one. Output The output consists of a line per input case, that contains the i-th fraction, with numerator and denominator separed by a slash ‘/’. The fraction should not be in the most simple form. Sample Input 6 Sample Output 1/3