pH

#include<iostream>
#include<algorithm>
#include<vector>
#include<functional>
#include<numeric>
#include<cstdlib>
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;
static inline void solve(){
    int n;cin>>n;
    V<int> h(n),w(n);
    for(auto& i:h) cin>>i;
    for(auto& i:w) cin>>i;
    V<V<int>> e(maxn);
    V<int> in(maxn,0),dsu(maxn);
    iota(dsu.begin(),dsu.end(),0);
    F<int(int)> find=[&](int x){
        return x==dsu[x]?x:dsu[x]=find(dsu[x]);
    };
    auto merge=[&](int a,int b){dsu[find(a)]=find(b);};
    for(int i=0;i<n;i++){
        e[h[i]].emplace_back(w[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((int)e[i].size()<in[i]) pos++,t=i;
        if(in[i]<(int)e[i].size()) neg++,s=i;
        if(abs((int)e[i].size()-in[i])>1) {
            cerr<<i<<' '<<in[i]<<' '<<e[i].size()<<endl;
            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(e[s=t=i].size()>0) break;
    for(int i=0;i<maxn;i++)
        if((in[i]||e[i].size())&&find(i)!=find(s)){
            cerr<<i<<endl;
            goto ICANT;
        }
    cout<<s<<' '<<t<<endl;
    return;
ICANT:
    cout<<-1<<endl;
}
int main(){
    int T=1;
    cin>>T;
    while(T--)
        solve();
    return 0;
}