#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include<queue>
#include<map>
using namespace std;
class Node 
{ 
    public:
    int left; 
    int right; 
    int hd; 
    int data; 
    Node(int data, int left, int right): data(data),right(right),left(left){}
}; 
vector<Node> v;
void topview(Node root) 
{ 
    if(root.data==-1)  return; 
     queue<Node>q; 
     map<int,int> m;  
     int hd=0; 
     root.hd=hd; 
       
    q.push(root); 
      
    while(q.size()) 
    { 
        hd=root.hd; 
        
        if(m.count(hd)==0)  m[hd]=root.data; 
        if(root.left!=-1) 
        { 
            v[root.left].hd=hd-1; 
            q.push(v[root.left]); 
        } 
        if(root.right!=-1) 
        { 
            v[root.right].hd=hd+1; 
            q.push(v[root.right]); 
        } 
        q.pop(); 
        root=q.front();  
    } 
      
     for(auto i=m.begin();i!=m.end();i++) 
    { 
        cout<<i->second<<" "; 
    } 
      
} 

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n,a,b;
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>a>>b;
        Node curr(i,a,b);
        v.push_back(curr);
    }
    topview(v[0]);
    return 0;
}