#include <bits/stdc++.h>

using namespace std;

void solve() {
	string parking;
	cin >> parking;
	int m = (int) parking.size();
	string waiting;
	cin >> waiting;
	int n = (int) waiting.size();
	vector<int> a;
	for (int i = 0; i < m; ) {
		if (parking[i] == 'X') {
			i++;
			continue;
		}
		int j = i;
		while (j < m && parking[j] == '.') {
			++j;
		}
		if (j - i > 1) {
			a.push_back(j - i);
		}
		i = j;
	}
	for (int i = 0; i < (int) a.size(); i++) {
		a[i]--;
		if (a[i] == 1) ++a[i];
	}
	int l = -1;
	int r = n + 1;
	while (l < r - 1) {
		int mid = (l + r) >> 1;
		int countCars = 0;
		int countAll = 0;
		for (int i = 0; i < mid; i++) {
			if (waiting[i] == 'C') ++countCars;
			++countAll;
		}
		vector<int> c(a);
		for (int i = 0; i < (int) c.size(); i++) {
			if ((c[i] & 1) && countCars > 0) {
				c[i] -= 3;
				--countCars;
				--countAll;
			}
		}
		for (int i = 0; i < (int) c.size(); i++) {
			if ((c[i] & 1)) ++c[i];
			if (countCars > 1) {
				int x = min(c[i] / 6, countCars / 2);
				c[i] -= 6 * x;
				countCars -= 2 * x;
				countAll -= 2 * x;
			}
		}
		int sum = 0;
		for (int i : c) {
			sum += i;
		}
		if (countAll * 2 >= sum) {
			r = mid;
		} else {
			l = mid;
		}
	}
	for (int i = 0; i <= l; i++) cout << "Y";
	for (int i = l + 1; i <= n; i++) cout << "N";
	cout << "\n";
}

int main() {
	ios::sync_with_stdio(false); cin.tie(NULL);
	int t;
	cin >> t;
	while (t--) {
		solve();
	}
}