/**
	author:  shobonvip
	created: 2025.04.04 21:20:53
**/

#include<bits/stdc++.h>
using namespace std;

//* ATCODER
#include<atcoder/all>
using namespace atcoder;
typedef modint998244353 mint;
//*/

/* BOOST MULTIPRECISION
#include<boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
//*/

typedef long long ll;

#define rep(i, s, n) for (int i = (int)(s); i < (int)(n); i++)
#define rrep(i, s, n) for (int i = (int)(n)-1; i >= (int)(s); i--)
#define all(v) v.begin(), v.end()

template <typename T> bool chmin(T &a, const T &b) {
	if (a <= b) return false;
	a = b;
	return true;
}

template <typename T> bool chmax(T &a, const T &b) {
	if (a >= b) return false;
	a = b;
	return true;
}

template <typename T> T max(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmax(ret, a[i]);
	return ret;
}

template <typename T> T min(vector<T> &a){
	assert(!a.empty());
	T ret = a[0];
	for (int i=0; i<(int)a.size(); i++) chmin(ret, a[i]);
	return ret;
}

template <typename T> T sum(vector<T> &a){
	T ret = 0;
	for (int i=0; i<(int)a.size(); i++) ret += a[i];
	return ret;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int n; cin >> n;
	vector<int> a(n), b(n);
	vector<int> deg(n);
	rep(i,0,n){ 
		cin >> a[i] >> b[i];
		if(a[i]==1){
			deg[i]++;
		}
		if(b[i]==2){
			deg[i]++;
		}
	}

	vector<int> b1list;
	rep(i,0,n){ 
		if (b[i]==1){ 
			b1list.push_back(i);
		}
	}

	vector ikeru(n, vector<int>(0));
	rep(i,0,n){
		if(a[i]==1){
			ikeru[i+1].push_back(i);
		}
		if(b[i]==2){
			int v=int(lower_bound(all(b1list),i)-b1list.begin());
			ikeru[b1list[v]].push_back(i);
		}
	}



	rep(i,0,n){
		if(deg[i]==1){
			continue;
		}
		int x=i;
		cout<<x+1<<'\n';
		while (!ikeru[x].empty()){
			x=ikeru[x][0];
			cout<<x+1<<'\n';
		}
	}


}