function getNode(llist, positionFromTail) {
    // Write your code here
    let index = 0
    let head = llist, prev = null
    
    while (head!==null){
        let temp = head.next
        head.next = prev //inc on linked list
        prev = head
        head = temp 
    }
   
    while(prev!==null){
        if(index == positionFromTail){
            return prev.data
        }
        prev = prev.next
        index++
    }

}