#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<(int)(n);i++)

int main() {
    int N;
    cin>>N;
    vector<int> p(N);
    rep(i,N) cin>>p.at(i);
    rep(i,N) p.at(i)--;
    vector<int> rp(N);
    rep(i,N) rp.at(p.at(i))=i;
    vector<int> nx(N); // 要素iの次の要素
    rep(i,N){
        if(rp.at(i)==N-1) nx.at(i)=-1;
        else nx.at(i)=p.at(rp.at(i)+1);
    }
    vector<int> stl(N,0);
    auto get_next=[&](auto self,int x){
        if(x==-1||!stl.at(x)) return x;
        return nx.at(x)=self(self,nx.at(x));
    };
    vector<int> ans;
    rep(i,N){
        if(stl.at(i)) continue;
        stl.at(i)=1;
        int j=get_next(get_next,i);
        if(j==-1){
            stl.at(i)=0;
            continue;
        }
        stl.at(j)=1;
        ans.push_back(i);
        ans.push_back(j);
    }
    for(int x:ans) cout<<x+1<<" ";
    cout<<"\n";
}