Linked List (C)

#include<stdio.h>

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

struct Node *Head, *Tail;

void InsertAfter(int Value, int Position);
void Delete(int Position);
void PrintList();

int main()
{
    Head = malloc(sizeof(struct Node));
    Tail = malloc(sizeof(struct Node));

    Head->Next = Tail;
    Head->Data = 0;
    Tail->Next = NULL;
    Tail->Data = 2146;

    char Input[5] = "Hello";
    int a, b;

    while (fgets(Input, 6, stdin) != NULL && Input[0] != 'q')
    {
        a = Input[2] - '0';
        b = Input[4] - '0'; //problem here

        if (Input[0] == 'i')
            InsertAfter(a,b);

        else if (Input[0] == 'd')
            Delete(a);

        else if (Input[0] == 'p')
            PrintList();
    }

    return 0;
}

void InsertAfter(int Value, int Position)
{
    struct Node *Iterator = Head;
    struct Node *InsertMe = malloc(sizeof(struct Node));

    int i;
    for (i = 0; i < Position && Iterator->Data != 2146; i++)
        Iterator = Iterator->Next;

    InsertMe->Data = Value;
    InsertMe->Next = Iterator->Next;
    Iterator->Next = InsertMe;

    printf("Inserted %d into position %d\n\n", Value, Position);
}

void Delete(int Position)
{
    struct Node *Iterator = Head->Next;
    struct Node *DeleteMe = malloc(sizeof(struct Node));

    int i;
    for (i = 0; i < Position && Iterator->Data != 2146; i++)
        Iterator=Iterator->Next;

    DeleteMe = Iterator->Next;
    Iterator->Next = DeleteMe->Next;

    printf("Deleted %d from position %d\n\n", DeleteMe->Data, Position);
    free(DeleteMe);
}

void PrintList()
{
    struct Node *Iterator = Head->Next;
    printf("Printing list:\n");
    while (Iterator->Data != 2146)
    {
        printf("%d ", Iterator->Data);
        Iterator = Iterator->Next;
    }
    printf("\n\n");
}

/*
abdul@debian:~/Programming/C$ make test
gcc LinkedList.c -o LinkedList
LinkedList.c: In function ‘main’:
LinkedList.c:17:9: warning: incompatible implicit declaration of built-in function ‘malloc’
  Head = malloc(sizeof(struct Node));
         ^
LinkedList.c: In function ‘InsertAfter’:
LinkedList.c:49:26: warning: incompatible implicit declaration of built-in function ‘malloc’
  struct Node *InsertMe = malloc(sizeof(struct Node));
                          ^
LinkedList.c: In function ‘Delete’:
LinkedList.c:65:26: warning: incompatible implicit declaration of built-in function ‘malloc’
  struct Node *DeleteMe = malloc(sizeof(struct Node));
                          ^
LinkedList.c:75:2: warning: incompatible implicit declaration of built-in function ‘free’
  free(DeleteMe);
  ^
./LinkedList
i 1 0
Inserted 1 into position 0

i 2 1
Inserted 2 into position 1

i 3 2
Inserted 3 into position 2

i 6 0
Inserted 6 into position 0

i 6 3
Inserted 6 into position 3

i 7 10
Inserted 7 into position 1

d 3
Deleted 6 from position 3

p
Printing list:
6 7 1 2 3
*/