import sys

# sys.setrecursionlimit(1000005)
# sys.set_int_max_str_digits(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
# inf = -1-(-1 << 31)
inf = -1-(-1 << 62)

# md = 10**9+7
md = 998244353

def solve():
    n = II()
    s = SI()
    cnt = 0
    for i in range(1, n-1):
        if s[i] == "-":
            if s[i-1] == "K": cnt += 1
            if s[i-1] == "P": cnt -= 1
            if s[i+1] == "K": cnt += 1
            if s[i+1] == "P": cnt -= 1
    if s[-1] == "K": cnt += 1
    if s[-1] == "P": cnt -= 1
    if s[0] == "K": cnt += 1
    if s[0] == "P": cnt -= 1

    print("P" if cnt < 0 else "K")

for _ in range(II()): solve()