#include<iostream>
#include<vector>
#include<algorithm>
#include<queue>
using namespace std;
using ll=long long;
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
template<class T> bool chmax(T &a, T b){if (a < b){a = b;return true;} else return false;}
template<class T> bool chmin(T &a, T b){if (a > b){a = b;return true;} else return false;}
void solve(){
int N;
string S;
cin>>N>>S;
vector<int>A(N),ind(N);
vector<bool>flag(N);
for(int i=0;i<N;i++){
cin>>A[i];
A[i]--;
ind[A[i]]++;
if(S[i]=='1')flag[i]=true;
}
queue<int>q;
for(int i=0;i<N;i++){
if(ind[i]==0)q.push(i);
}
vector<int>ans;
while(q.size()){
int x=q.front();
q.pop();
if(ind[A[x]]>0){
ind[A[x]]--;
if(flag[x]){
flag[x]=false;
flag[A[x]]=!flag[A[x]];
ans.push_back(x+1);
}
if(ind[A[x]]==0){
q.push(A[x]);
}
}
}
for(int i=0;i<N;i++){
if(ind[i]>0&&flag[i]){
int at=i;
bool light=true;
int x=1,y=1;
while(1){
at=A[at];
if(at==i)break;
if(flag[at]){
light=!light;
}
if(light)x++;
y++;
ind[at]--;
}
if(light){
cout<<-1<<"\n";
return;
}
light=true;
while(1){
if(light==(x<=y-x)){
ans.push_back(at+1);
}
at=A[at];
if(at==i)break;
if(flag[at]){
light=!light;
}
}
}
}
cout<<(int)ans.size()<<"\n";
for(auto a:ans)cout<<a<<" ";
cout<<"\n";
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int T;
cin>>T;
while(T--){
solve();
}
}
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