Hi Grigore,

Well, I was hoping to help you to change the problem...

I wrote a C program that does the four aritmetic operations for and accepts two strings as operands. It is extremely fast, regardless of the length operands or the operation. It works only for integers, but I guess it can be improved. I don't know if you can use it but I can send you the source code.

I'm going to send you a private message, in the sweet romanian language...