import sys
input = sys.stdin.readline


def solve(n, s):
    score = 0
    for ss in s.split('-'):
        if not(ss):
            continue
        lis = [ss[0], ss[-1]]
        score += ('K' in lis) - ('P' in lis)
    return 'K' if(score >= 0) else 'P'


t = int(input())
for _ in [0] * t:
    n = int(input())
    s = input()[:-1]
    print(solve(n, s))