#include <bits/stdc++.h>
using namespace std;

#define all(x) ::begin(x), ::end(x)
#define tsolve int t; cin >> t; while (t--) solve
#define sz(x) (int)::size(x)
using ll = long long;
using ld = long double;

ll n;
string s;

void solve() {
    cin >> n;
    cin >> s;

    ll w = 0;
    bool r = false;
    for (ll i = 0; i < n; ++i) {
        if (s[i] == 'W') {
            if (r) {
                --w;
                if (w < 0) {
                    cout << "NO\n";
                    return;
                }
            }
            else {
                ++w;
            }
        }
        else r = true;
    }
    cout << (w % 2 == 0 ? "YES" : "NO") << '\n';
}

int main() {
    cout.tie(0)->sync_with_stdio(false);
    cout << setprecision(16);
    tsolve();
}