soldier* rearrange_circle(soldier* head){
    soldier *temp, *newHead;
    temp =(soldier *) malloc(sizeof(soldier));
    temp=last;
    while(temp->prev != last){
        temp=temp->prev;
        if (newHead == NULL){
            temp->next = temp->prev = temp;
            newHead = temp;
            return;
        }
        last = newHead->prev;
        temp->next = newHead;
        newHead->prev = temp;
    }
    if (newHead == NULL){
            temp->next = temp->prev = temp;
            newHead = temp;
            return;
    }
    last = newHead->prev;
    temp->next = newHead;
    newHead->prev = temp;
    temp->prev = last;
    return newHead;
}