#include <stdio.h>
#include <stdlib.h>

struct node {
    struct node *next;
    char         character;
};

// count_vowel_word_boundaries should return the number of vowel word boundaries
// in the given linked list.
//
// A vowel word boundary occurs when a node containing a vowel is immediately
// followed by a node containing a consonant.
// - The list will only contain lowercase characters (from a to z).
// - A vowel is one of the following characters: a, e, i, o, u.
// - A consonant is any character that is not a vowel.
int count_vowel_word_boundaries(struct node *head) {
    // PUT YOUR CODE HERE, DON'T FORGET TO CHANGE THE RETURN!
    return 42;
}

////////////////////////////////////////////////////////////////////////
//                    DO NOT CHANGE THE CODE BELOW                    //
////////////////////////////////////////////////////////////////////////

int count_vowel_word_boundaries(struct node *head);
struct node *list_from_string(char *string);


// DO NOT CHANGE THIS MAIN FUNCTION
int main(int argc, char *argv[]) {
    // create linked list from command line arguments
    struct node *head = NULL;
    if (argc > 1) {
        head = list_from_string(argv[1]);
    }

    // If you're getting an error here,
    // you have returned an uninitialized value
    printf("%d\n", count_vowel_word_boundaries(head));
    
    return 0;
}

// DO NOT CHANGE THIS FUNCTION
// create a linked list of chars from a string
struct node *list_from_string(char *string) {
    struct node *head = NULL;
    struct node *tail = NULL;

    for (int i = 0; string[i] != '\0'; i++) {
        struct node *new = malloc(sizeof(struct node));
        new->next = NULL;
        new->character = string[i];

        if (head == NULL) {
            head = new;
            tail = new;
        } else {
            tail->next = new;
            tail = new;
        }
    }

    return head;
}