int is_self (int n)
{
        int param_1, param_2;

        if (sod(n) % 9 == 0)                                    /*orismos protis parametrou elegxou kaprekar gia ton an exoume self number*/
                param_1 = 9;
        else param_1 = sod(n) % 9;

        if ( param_1 % 2 == 0)                                  /*orismos deuteris parametrou elegxou kaprekar gia to an exoume self number*/
                param_2 = param_1 / 2;
        else 
                param_2 = (param_1 + 9) / 2;