def solve():
    N = int(input())
    S = f"*{input().strip()}"

    Mod = 998244353
    inv = [0] * (N + 2); inv[1] = 1
    for x in range(2, N + 2):
        q, r = divmod(Mod, x)
        inv[x] = (- q * inv[r]) % Mod

    total = 0
    g = 0
    for i in range(1, N + 1):
        if i < N and S[i] == 'G':
            g += 1
            continue

        a = (g + 1) * (g + 2) % Mod
        total += a * inv[i + 1]; total %= Mod
        g = 0

    coef = (N + 1) * inv[2] % Mod
    return coef * total % Mod

#==================================================
import sys
input = sys.stdin.readline
write = sys.stdout.write

T = int(input())
write("\n".join(map(str, [solve() for t in range(T)])))