#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll=long long;

int main()
{
    int n;
    cin>>n;
    vector<int> a(n),b(n);
    for(int i=0;i<n;i++)cin>>a[i]>>b[i];
    vector<int> nxt(n,-1);
    {
        int p=-1;
        for(int i=0;i<n;i++){
            if(a[i]==1){
                nxt[i+1]=i;
            }
            if(b[i]==2){
                p=i;
            }else if(b[i]==1){
                nxt[i]=p;
            }
        }
    }
    for(int i=0;i<n;i++){
        if(a[i]==1||b[i]==2)continue;
        cout<<i+1<<endl;
        int x=i;
        while(nxt[x]!=-1){
            cout<<nxt[x]+1<<endl;
            x=nxt[x];
        }
    }
    return 0;
}