INTERVIEW Test - Please help me solve : I got a really interesting question at a company, and I can't seem to find an answer at all. It really bothers me, please help me.

        [code]
    
      #include <cstdio>
    int main()
    {
        int num = 123456789;
        int res = 0;
        for (int i = 0; i<111111111; i++)
        {
        res=(res+num)%1000000000;
        }
        printf("06 %09d", res);
        return 0;
        }
        [/code]

I should declare num so the output is my mobile number, 305089171.
Any idea how to do that?
