import sys
input = sys.stdin.readline

def solve(s):
    k, p = 0, 0
    s += "-"
    N = len(s)
    for i in range(N - 1):
        if s[i] != s[i + 1] and s[i] != "-":
            if s[i] == "K":
                k += 1
            else:
                p += 1
    return k >= p

T = int(input())
for _ in range(T):
    N = int(input())
    if solve(input().rstrip()):
        print("K")
    else:
        print("P")