#include<stdio.h>
#include<stdlib.h>
typedef struct node{
    int data;
    struct node *next;
    struct node *prev;
}Node;
Node *head=NULL, *tail, *iter;
void create(int num){
    Node *newNode=(Node*)malloc(1*sizeof(Node));
    newNode->data=num;
    newNode->next=NULL;
    newNode->prev=NULL;
    if(head==NULL){
        head=newNode;
        tail=newNode;
    }
    else{
        newNode->prev=tail;
        tail->next=newNode;
        tail=newNode;
    }
    
}
void deletion(int val){
    iter=head->next;
    if(head->data==val){
        head=head->next;
        head->prev=NULL;
    }
    else if(tail->data==val)
        tail->prev->next=NULL;
    else{
        while(iter!=NULL){
            if(iter->data==val){
                iter->next->prev=iter->prve;
                iter->prev->next=iter->next;
                break;
            }
            iter=iter->next;
        }
    }
    
}