Retrieve characters after nth occurence of a string

Hi,

I have this data in my rows:

1. BBY TOYS SJC 15
2. BBY TOYS CUP 25
3. BBY TOYS SKU(15X10)10
4. SKU BOX 1000
5. SKU BOX 10000

I need to dynamically retrieve the following from each:

1. 15
2. 25
3. 10
4. 1000
5. 10000

I used the following formula:
=RIGHT(,LEN()-FIND(" ",,10))

It works for all the above rows except the 3rd, for which it retrieves: SKU(15X10)10
Can you please help? Is there a better formula that I can use?

Thanks