//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define all(a) (a).begin(), (a).end()
using ll = long long;
const ll INF32 = 2e9;
const ll INF64 = 4e18;

void printYN(bool ok){
    if(ok)cout << "Yes" << endl;
    else cout << "No" << endl;
    return;
}

void solve() {
    string R, S; int K;
    cin >> R >> S >> K;
    if(S[0]=='W'){
        rep(i, K)R[i] = 'A';
        bool exist_W = false; int cnt_q = 0;
        rep(i, R.size()){
            if(R[i]=='W')exist_W = true;
            if(R[i]=='?')cnt_q++;
        }
        if(!exist_W&&cnt_q==1)rep(i, R.size()){
            if(R[i]=='?')R[i] = 'W';
        }
        cout << R << endl;
    }else {
        bool case1 = false, case2 = true;
        rep(i, R.size()){
            if(i<K&&(R[i]=='?'||R[i]=='W'))case1 = true;
            if(R[i]=='W')case2 = false;
        }
        if(case1&&case2){
            cout << R << endl;
        }
        else if(case1){
            bool exist_W = false; int cnt_q = 0;
            rep(i,K){
                if(R[i]=='W')exist_W = true;
                if(R[i]=='?')cnt_q++;
            }
            if(!exist_W&&cnt_q==1)rep(i, K){
                if(R[i]=='?')R[i] = 'A';
            }
            cout << R << endl;
        }
        else {
            rep(i, R.size())R[i] = 'A';
            cout << R << endl;
        }
    }
}

int main() {
    int T;
    cin >> T;
    rep(i,T)solve();
    return 0;
}