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#include<iostream>
#include<algorithm>
#include<vector>
#include<functional>
#include<numeric>
#include<cstdlib>
#include<cassert>
#define endl '\n'
using namespace std;
namespace {
    template<typename T> using V=vector<T>;
    template<typename T1,typename T2=T1> using P=pair<T1,T2>;
    template<typename T> using F=function<T>;
    using ll=long long;
}
constexpr int maxn=1e6+5;
int n=0,h[maxn],w[maxn],in[maxn],out[maxn],dsu[maxn];
int find(int x,int d=0){
    assert(d<maxn);
    return x==dsu[x]?x:dsu[x]=find(dsu[x],d+1);
}
void merge(int a,int b){dsu[find(a)]=find(b);}
void init(){
    iota(dsu,dsu+maxn,0);
}
void reinit(){
    for(int i=0;i<n;i++){
        in[h[i]]=in[w[i]]=out[h[i]]=out[w[i]]=0;
        dsu[h[i]]=h[i],dsu[w[i]]=w[i];
    }
}
void solve(){
    cin>>n;
    for(int i=0;i<n;i++) cin>>h[i];
    for(int i=0;i<n;i++) cin>>w[i];
    for(int i=0;i<n;i++)
        out[h[i]]++,in[w[i]]++,merge(h[i],w[i]);
    int pos=0,neg=0,s=-1,t=-1;
    for(int i=0;i<maxn;i++){
        if(out[i]<in[i]) pos++,t=i;
        if(in[i]<out[i]) neg++,s=i;
        if(abs(out[i]-in[i])>1) goto ICANT;
    }
    if(P{pos,neg}!=P{0,0}&&P{pos,neg}!=P{1,1}) goto ICANT;
    if(!~s) for(int i=0;i<maxn;i++)
        if(out[s=t=i]>0) break;
    for(int i=0;i<maxn;i++)
        if((in[i]||out[i])&&find(i)!=find(s)) goto ICANT;
    cout<<s<<' '<<t<<endl;
    return;
ICANT:
    cout<<-1<<endl;
}
int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int T=1;
    cin>>T;
    init();
    while(T--)
        solve(),reinit();
    return 0;
}