import java.util.Scanner; class DLLNode { protected E element; protected DLLNode pred, succ; public DLLNode(E elem, DLLNode pred, DLLNode succ) { this.element = elem; this.pred = pred; this.succ = succ; } @Override public String toString() { return "<-" + element.toString() + "->"; } } class DLL { private DLLNode first, last; public DLL() { // Construct an empty SLL this.first = null; this.last = null; } public void deleteList() { first = null; last = null; } public int length() { int ret; if (first != null) { DLLNode tmp = first; ret = 1; while (tmp.succ != null) { tmp = tmp.succ; ret++; } return ret; } else return 0; } public void insertFirst(E o) { DLLNode ins = new DLLNode(o, null, first); if (first == null) last = ins; else first.pred = ins; first = ins; } public void insertLast(E o) { if (first == null) insertFirst(o); else { DLLNode ins = new DLLNode(o, last, null); last.succ = ins; last = ins; } } public void insertAfter(E o, DLLNode after) { if (after == last) { insertLast(o); return; } DLLNode ins = new DLLNode(o, after, after.succ); after.succ.pred = ins; after.succ = ins; } public void insertBefore(E o, DLLNode before) { if (before == first) { insertFirst(o); return; } DLLNode ins = new DLLNode(o, before.pred, before); before.pred.succ = ins; before.pred = ins; } public E deleteFirst() { if (first != null) { DLLNode tmp = first; first = first.succ; if (first != null) first.pred = null; if (first == null) last = null; return tmp.element; } else return null; } public E deleteLast() { if (first != null) { if (first.succ == null) return deleteFirst(); else { DLLNode tmp = last; last = last.pred; last.succ = null; return tmp.element; } } // else throw Exception return null; } @Override public String toString() { String ret = new String(); if (first != null) { DLLNode tmp = first; ret += tmp + "<->"; while (tmp.succ != null) { tmp = tmp.succ; ret += tmp + "<->"; } } else ret = "Prazna lista!!!"; return ret; } public DLLNode getFirst() { return first; } public DLLNode getLast() { return last; } } public class NegativePositive { public static DLL negative_positive(DLL head) { // vashiot kod tuka } public static void main(String[] args) { Scanner in = new Scanner(System.in); int n = in.nextInt(); DLL list = new DLL(); for (int i = 0; i < n; i++) { list.insertLast(in.nextInt()); } in.close(); System.out.println(negative_positive(list)); } }