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

struct pile
{
	int tete;
	char ple[10];
};

typedef struct pile pile;

int empty(pile *p)
{
	if(p==NULL)
	{
		return 1;
	}
	return p->tete==0;
}

char pop(pile **p)
{
	(*p)->tete--;
	return (*p)->ple[(*p)->tete];
}

void push(pile **p,char v)
{
	if (*p==NULL)
	{
		pile *new=malloc(sizeof(pile));
		new->tete=0;
		*p=new;
		push(p,v);
	}else
	{
	(*p)->ple[(*p)->tete]=v;
	(*p)->tete++;
	}
}

char top(pile **p)
{
	char temp = pop(p);
	push(p,temp);
	return temp;
}

void clear(pile **p)
{
	while(!empty((*p)))
	{
		pop(p);
	}
}