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

struct snode{
    int data;
    struct snode *next;
};

void push(int data, struct snode *stack_buffer){
    struct snode *new_node= (struct snode *)malloc(sizeof(struct snode));

        new_node->next=stack_buffer;
        new_node->data=data;
        stack_buffer=new_node;

}

int pop(struct snode *stack_buffer){
    if(stack_buffer)
    {
        int elem=stack_buffer->data;
        struct snode *new_node=stack_buffer;
        stack_buffer=new_node->next;
        return elem;
    }
    else return -1;
}



int main()
{
    struct snode *stack_buffer=NULL;
    push(4,stack_buffer);
    push(1,stack_buffer);
    push(5,stack_buffer);
    push(8,stack_buffer);

    int elem=pop(stack_buffer);
    printf("%d",elem);

    return 0;
}