#include
#include
#include

using namespace std;

int main() {
char func[100001] = { 0, };
char arr[300102] = { 0, };
int T, N;
char c;
int count = 0, check = 0;
int front, back;

cin >> T;

for (int i = 0; i < T; i++) {

count = 0;
check = 0;
cin >> func >> N;
cin >> arr;

front = 1;
back = strlen(arr)-2;

for (int j = 0; func[j] != '\0' ; j++) {
if (func[j] == 'D') {
count++;
}
}

if (count > N) {
cout << "error" << endl;
continue;
}

for (int j = 0; func[j] != '\0'; j++) {
if (func[j] == 'R') {
check++;
}
else if (func[j] == 'D') {

if (check % 2 == 0) {

while (arr[front] != ',') {
front++;
}

front++;
}
else {
while (arr[back] != ',') {
back--;
}
back--;
}
}
}

cout << '[';
if (check % 2 == 0) {
for (int j = front; j <=back; j++) {
cout << arr[j];
}
}
else {
for (int j = back; j>=front; j--) {
cout << arr[j];
}
}
cout << ']' << endl;

}
}