
int main(int argc, char **argv) {
    // TODO: Verify that command line arguments are valid.
     if (argc < 2 || argc > 2){
        return 2;
    }
    else{
        int sin_number = strtol(argv[1], NULL, 10);
        int array[9];

        if ((populate_array(sin_number, array) | check_sin(array)) == 1){
        printf("Invalid SIN \n");
        return 1;
        }

        else{
             printf("Valid SIN\n");
    // TODO: Parse arguments and then call the two helpers in sin_helpers.c
    // to verify the SIN given as a command line argument.

   
        return 0;
    }
    
    
    }
}
why is my main not running? I get an error saying implicit declaration of helper function