typedef struct MyLinkedList {
    int val;
    struct MyLinkedList *next;
} MyLinkedList;

MyLinkedList* myLinkedListCreate() {
    MyLinkedList *newList = malloc(sizeof(MyLinkedList));
    newList->next = NULL;
    return newList;
}

int myLinkedListGet(MyLinkedList* obj, int index) {
    MyLinkedList *tmp = obj->next;
    while (index-- > 0 && tmp != NULL) {
        tmp = tmp->next;
    }
    if (tmp == NULL) {
        return -1;
    }
    else {
        return tmp->val;
    }
}

void myLinkedListAddAtHead(MyLinkedList* obj, int val) {
    MyLinkedList *newNode = malloc(sizeof(MyLinkedList));
    newNode->val = val;
    if (obj->next != NULL) {
        newNode->next = obj->next;
    }
    else {
        newNode->next = NULL;
    }
    obj->next = newNode;
}

void myLinkedListAddAtTail(MyLinkedList* obj, int val) {
    MyLinkedList *tmp = obj;
    MyLinkedList *newNode = malloc(sizeof(MyLinkedList));
    newNode->val = val;
    newNode->next = NULL;
    while (tmp->next != NULL) {
        tmp = tmp->next;
    }
    tmp->next = newNode;
}

void myLinkedListAddAtIndex(MyLinkedList* obj, int index, int val) {
    MyLinkedList *tmp = obj;
    MyLinkedList *newNode = malloc(sizeof(MyLinkedList));
    newNode->val = val;
    while (tmp->next != NULL && index-- > 0) {
        tmp = tmp->next;
    }
    if (index <= 0) {
        if (tmp->next == NULL) {
            newNode->next = NULL;
        }
        else {
            MyLinkedList *tmpNode = tmp->next;
            newNode->next = tmpNode;
        }
        tmp->next = newNode;
    }
}

void myLinkedListDeleteAtIndex(MyLinkedList* obj, int index) {
    MyLinkedList *tmp = obj;
    while (index-- > 0 && tmp->next != NULL) {
        tmp = tmp->next;
    }

    if (index != 0) {
        MyLinkedList *tmpNode1 = tmp->next;
        if (tmpNode1 != NULL) {
            MyLinkedList *tmpNode2 = tmp->next->next;
            tmp->next = tmpNode2;
        }
        free(tmpNode1);
    }
}

void myLinkedListFree(MyLinkedList* obj) {
    MyLinkedList *tmpNode;
    while (obj != NULL) {
        tmpNode = obj;
        obj = obj->next;
        free(tmpNode);
    }
}