bool palindrom(node *l){
    node *q,*p,*t;
    q = l;
    p = NULL;
    while(q)
        if(!p){
        p = new node;
        p->key = q->key;
        p->next = NULL;
        q = q->next;
    }
    else{
        t = new node;
        t->key = q->key;
        t->next = p;
        p = t;
        q = q->next;
    }
    while(p){
        if(p->key != l->key)
            return 0;
        p = p->next;
        l = l->next;
    }
    return 1;
}