struct Node {
    int Data;
    Node* next;
};

for (int i = 0; i < 5; i++)
        a = add(a, i);

Node* add(Node *head, int Value)
{
    Node *New = (Node*)malloc(sizeof(Node));
    New->Data = Value;
    New->next = head;
    return New;
}

Node* Find(Node *head, int Value)
{
    while (head)
    {
        if (head->Data == Value)
            return head;
        head = head->next;
    }
    return NULL;
}

Node* add1(Node* head,Node* del)
{
    Node *New = (Node*)malloc(sizeof(Node));
    New->Data = 777;
    del->next = New;
    New->next = del->next->next;
    return head;
}