#include #pragma GCC optimize("Ofast") #define _GLIBCXX_DEBUG using namespace std; using std::cout; using std::cin; using std::endl; using ll=long long; using ld=long double; ll ILL=2167167167167167167; const int INF=2100000000; const ll mod=998244353; #define rep(i,a) for (ll i=0;i using _pq = priority_queue, greater>; template ll LB(vector &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();} template ll UB(vector &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();} template bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;} template bool chmax(T &a,const T &b){if(a void So(vector &v) {sort(v.begin(),v.end());} template void Sore(vector &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});} void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";} template void vec_out(vector &p){for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<>t; rep(i,t) solve(); } void solve(){ int N; cin>>N; string S,T; cin>>S>>T; auto f=[](char a,char b)->char{ if(a==b) return '0'; return '1'; }; vector ans; rep(i,N){ if(S[i]==T[i]&&S[i+N]==T[i+N]) continue; else if(f(S[i],S[i+1])==T[i]&&T[i+1]==S[i]){ ans.push_back(i); ans.push_back(i+1); }else if(S[i+1]==T[i]&&f(S[i],S[i+1])==T[i+N]){ ans.push_back(i+N); ans.push_back((i+N+1)%(2*N)); }else{ cout<<"-1\n"; return ; } } cout<