#include<bits/stdc++.h>
using namespace std;
const int N=3e5+10;
int n,a[N],head;
int main()
{
	scanf("%d",&n);
	for(int i=1,x;i<=n;i++)
	{
		scanf("%d",&x);
		if(x==-1)head=i;
		else a[x]=i;
	}
	for(int i=head;i;i=a[i])printf("%d ",i);
	return 0;
}