Stack write myself

#include <stdio.h>
#include <stdlib.h>
#define TRUE 1
#define FALSE 0

typedef struct _node
{
	int data;
	struct _node* next;
}Node;

typedef struct _stack
{
	Node* tail;
	int Number;
}Stack;

void Init(Stack* copy)
{
	copy->tail = NULL;
	copy->Number = 0;
}

void Push(Stack* copy, int data)
{
	Node* newNode = (Node*)malloc(sizeof(Node));
	newNode->data = data;
	
	if (copy->tail == NULL)
	{
		copy->tail = newNode;
		newNode->next = newNode;
	}
	newNode->next = copy->tail->next;
	copy->tail->next = newNode;
	
	(copy->Number)++;
}

int Pop(Stack* copy)
{
	if (copy->tail == NULL)
	{
		return -1;
	}
	else
	{
		Node* temp = copy->tail->next;
		int temp_data = temp->data;
		
		copy->tail->next = temp->next;
		(copy->Number)--;
		free(temp);
		return temp_data;
	}
}

int Peek(Stack* copy)
{
	if (copy->tail == NULL)
	{
		return -1;
	}

	return copy->tail->next->data;
}

int Count(Stack* copy)
{
	return copy->Number;
}

int Empty(Stack* copy)
{
	if (copy->tail == NULL)
		return TRUE;
	else
		return FALSE;
}

int main(void)
{
	Stack box;
	Init(&box);

	Push(&box, 10);
	Push(&box, 20);
	Push(&box, 30);

	printf("Current Number of Box: %d\n", Count(&box));
	
	printf("Pop data: %d\n", Pop(&box));

	printf("Current Number of Box: %d\n", Count(&box));

	printf("Peek data: %d\n", Peek(&box));

	return 0;
}