int main(int argc, char **argv) {
    // TODO: Verify that command line arguments are valid.
        if (argc != 2){
                return 2;
        }
    // TODO: Parse arguments and then call the two helpers in sin_helpers.c
    // to verify the SIN given as a command line argument.
        int *populated_array;
        populate_array((int) argv[1], populated_array);
        int b = check_sin(populated_array);
        if (b == 0){
                printf("%s\n", "Valid SIN");
                return 0;
        } else{
                printf("%s\n", "Invalid SIN");
                return 1;
        }

}

If the user calls the program with too few or too many arguments, the program should not print anything, but should return from main with return code 2. main should return 0 when the program runs successfully and the SIN is valid and 1 when the program runs successfully but the SIN is invalid.