580 B | 580 chars
#include <iostream>
#include <algorithm>
using namespace std;
int N,size,heap[100200];
bool compare(int a, int b)
{
int A=a;
int B=b;
if(A<0) A=-A;
if(B<0) B=-B;
if(A>B) return true;
else if((a>0&&b<0)&&A==B)
{
return true;
}
else return false;
}
int main()
{
scanf("%d",&N);
for(int x=0; x<N; x++)
{
int a;
scanf("%d",&a);
if(a!=0)
{
heap[size++]=a;
push_heap(heap,heap+size,compare);
}
else if(a==0)
{
if(size<1) printf("0\n");
else
{
printf("%d\n",heap[0]);
pop_heap(heap,heap+size,compare);
size--;
}
}
}
}