I have a problem with this code?

Code:
            int a = ds.Tables[0].Rows.Count;
            a = a + 1;
            if (a < 10)
            {
                a = "0" + a;
                a = cint(a);
            }
I want in the first place to check if the number is less than 10. If it is, I am going to append "0" in front of the integer number. Example. if the value of a is 9 then the program will add 0 and the value will be 09.

I always get this error with this code:

Cannot implicitly convert type 'string' to 'int'. The name 'cint' does not exist in the current context.