def solve():
    n = int(input())
    S = input()
    T = S.split("-")
    c = 0
    for t in T:
        if t == "":
            continue
        elif t[0] == t[-1]:
            if t[0] == "P":
                c += 1
            else:
                c -= 1
    return c > 0


for _ in range(int(input())):
    if solve():
        print("P")
    else:
        print("K")