#include<stdio.h>
#include<stdlib.h>
typedef struct node{
    int n;
    struct node*next;
}node;
node*head=NULL,*tail;
void create(int num){
    node *newnode(node*)malloc(1*sizeof(node));
    newnode->data=num;
    newnode->next=NULL;
    if(head==NULL) {
        head=newnode;
        tail=newnode;
        else
        tail->next=newnode;
        tail=newnode;
    }
}
void insertion(int,val,int pos,intsize){
    node*newnode=(node*)malloc(1*sizeof(node));
    newnode->data=val;
    newnode->next=NULL;
    if(pos==1){
        newnode->next=head;
        head=newnode
    }
    else if(pos==size+1){
        tail->next=newnode;

    }
    }
}