#include #include using namespace std; using namespace atcoder; typedef long long int ll; typedef long double ld; #define FOR(i,l,r) for(ll i=l;i=l;i--) #define RREP(i,n) RFOR(i,0,n) #define ALL(x) x.begin(),x.end() #define PA pair #define F first #define S second #define BS(A,x) binary_search(ALL(A),x) #define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin()) #define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin()) #define COU(A,x) (UB(A,x)-LB(A,x)) templateusing min_priority_queue=priority_queue,greater>; using mint=modint1000000007; //using mint=modint998244353; void chmax(ll&a,ll b){a=max(a,b);} void chmin(ll&a,ll b){a=min(a,b);} void print(vector&A){REP(i,A.size()){if(i)cout<<" ";cout<>T; while(T--){ ll N;string S;cin>>N>>S; vectorX(N+1); REP(i,N){ if(S[i]=='A')X[i+1]=X[i]+1; else X[i+1]=X[i]-1; } vectorMI=X; RREP(i,N)chmin(MI[i],MI[i+1]); string ans; REP(i,N){ if(X[i]==MI[i+1]){ ans+="AB"; ll j=i++; while(i<=N&&X[i]>X[j])i++; i--; } else if(X[i]m)i++; i--; } } cout<