Remove duplicates from an unsorted linked list without using any extra space [Javascript]

// defining a linked list let LL = {data: 1, next: {data: 2, next: {data: 3, next: {data: 1, next: {data: 2, next: {data: 5, next: {data:1, next: null}}}}}}}; let HEAD = LL; while(HEAD != null) { let HEAD2 = HEAD; while( HEAD2.next != null) { if(HEAD.data == HEAD2.next.data) { HEAD2.next = HEAD2.next.next; } else { HEAD2 = HEAD2.next; } } HEAD = HEAD.next; } console.log(LL);