#include <stdio.h>

#include "stack.h"

 int main(int argc, char *argv[])
 {
    push(1); push(4); push(7); push(9);

    printf("%d\n", pop());
    printf("%d\n", pop());
    printf("%d\n", pop());
    printf("%d\n", pop());
    printf("%d\n", pop());
 }