382. Cantor Function
Time limit per test: 0.25
second(s)
Memory limit: 262144
kilobytes
input: standard
output: standard
The Cantor function
f(
x) (see picture) is defined as the function on [0, 1] as follows:
If x belongs to Cantor set ( where n_{i} are different positive integers), then . f is continuous and monotonous function.
In 2004, Gorin and Kukushkin showed that is rational. You are to find I_{n} and output it as irreducible fraction.
Input
First line contains one integer number n (0 ≤ n ≤ 50).
Output
You should output I_{n} in the form p/q, where p and q are the numerator and the denominator of I_{n} respectively. Note that p and q must be natural and (p, q) must be equal to 1. You should output p and q without leading zeroes.
Example(s)
sample input

sample output

0

1/1

sample input

sample output

1

1/2

sample input

sample output

2

3/10
