#pragma GCC optimize ("O3,inline,omit-frame-pointer,no-asynchronous-unwind-tables,fast-math")
#include <bits/stdc++.h>
#include <unordered_map>
#include <stdlib.h>
using namespace std;
#define rep(i, a, n) for(ll i = a; i < n; i++)
#define rrep(i, a, n) for(ll i = a; i >= n; i--)
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
//constexpr ll MOD = 1000000007;
constexpr ll MOD = 998244353;
constexpr int IINF = 1001001001;
constexpr ll INF = 1LL<<60;
template<class t,class u> void chmax(t&a,u b){if(a<b)a=b;}
template<class t,class u> void chmin(t&a,u b){if(b<a)a=b;}
 


int main() {
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    ll n; cin >> n;
    vector<ll> pre(n,-1);
    vector<ll> next(n,-1);
    ll num2 = -1;
    rep(i,0,n){
        ll a, b; cin >> a >> b;
        if(a == 1) pre[i] = i+1, next[i+1] = i;
        if(b == 2) num2 = i;
        if(b == 1) pre[num2] = i, next[i] = num2;
    }
    rep(i,0,n){
        ll now = i;
        if(pre[i] == -1){
            cout << i+1 << endl;
            while(next[now] != -1){
                now = next[now];
                cout << now+1 << endl;
            }
        }
    }
    return 0;
}