#include<bits/stdc++.h>
using namespace std;
#define pb push_back
const int lim=5e5+100;
void solve1(){
string s;
cin>>s;
int n=s.size();
int ty[n]{};
int haveemp=0;
vector<int>pools[2];
for(int i=0;i<n;i++){
if(s[i]=='('){
haveemp++;
}else if(1<haveemp){
pools[0].pb(i);
haveemp-=2;
}else if(haveemp){
pools[1].pb(i);
ty[i]=1;
haveemp=0;
}else if(pools[0].size()){
int toconvert=pools[0].back();
pools[0].pop_back();
ty[toconvert]=ty[i]=1;
pools[1].pb(i);
pools[1].pb(toconvert);
}else if(pools[1].size()){
int toconvert=pools[1].back();
pools[1].pop_back();
ty[i]=2;
ty[toconvert]=3;
}else{
cout<<"impossible\n";
return;
}
}
if(haveemp){
cout<<"impossible\n";
return;
}
int needgreen=0,needred=0,needblue=0;
string ans=string(n,' ');
for(int i=n-1;0<=i;i--){
if(s[i]=='('){
if(needgreen){
ans[i]='G';
needgreen--;
}else if(needred){
ans[i]='R';
needred--;
}else if(needblue){
ans[i]='B';
needblue--;
}
}else if(ty[i]==0){
ans[i]='G';
needred++,needblue++;
}else if(ty[i]==1){
ans[i]='G';
needgreen++;
}else if(ty[i]==2){
ans[i]='B';
}else{
ans[i]='R';
needgreen++;
}
}
cout<<ans<<"\n";
}
void solve2(){}
int main(){
#ifdef Local
freopen(".in","r",stdin);
freopen(".out","w",stdout);
#endif
int _;
cin>>_;
if(_==1){
int t;
cin>>t;
while(t--)solve1();
}else{
int t;
cin>>t;
while(t--)solve2();
}
}
