typedef struct
{
    int top;
    int items[100];
} Stack;
void initialize(Stack *s)
{
    s->top=0;
}
void push(Stack *s,int value)
{
    s->items[s->top++]=value;
}
int pop(Stack *s)
{
    return s->items[--s->top];
}
int isfull(Stack *s)
{
    return s->top<100?0:1 ;
}
int isempty(Stack *s)
{
    return s->top==0?1:0;
}