### Problem Statement

You will be given B0, the first element of our sequence. The following equation must hold for all n > 0:
`        0  =  B0 + n+1C1B1 + n+1C2B2 + ... + n+1CnBn `
Here aCb is the standard binomial coefficient (see the notes). Return the value Bpos in the form "p/q" (quotes for clarity) where p and q are integers with no extra leading zeros and no common factors (other than 1). The denominator q must always be positive. If the returned value is 0 then return "0/1".

### Definition

 Class: BComputation Method: getValue Parameters: int, int Returns: String Method signature: String getValue(int B0, int pos) (be sure your method is public)

### Notes

-aCb has value a!/(b!(a-b)!) where a! = a*(a-1)*...*2*1.

### Constraints

-B0 will be between -100 and 100, inclusive.
-pos will be between 0 and 15, inclusive.

### Examples

0)

 `1` `0`
`Returns: "1/1"`
 Here we simply return B0.
1)

 `1` `1`
`Returns: "-1/2"`
 Using the given formula, we can compute B1 = -B0/2C1.
2)

 `100` `11`
`Returns: "0/1"`
3)

 `92` `12`
`Returns: "-31786/1365"`

#### Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=6777

#### Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=10112&pm=6777