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

char *stack;
int stkptr;

void push(char c){
	stack[stkptr++] = c;
}
char pop(){
	stkptr--;
	return stack[stkptr];
}
int main(int argc, char *argv[]){
	stkptr=0;
	stack = new char[100];

	push('a');
	push('b');
	push('c');
	printf("%c\n",pop());
	printf("%c\n",pop());
	printf("%c\n",pop());
}