import sys
input = sys.stdin.readline

def solve(n, s):
    x = 0
    for ss in s.split('-'):
        if(len(ss) == 0):
            continue
        if(ss[0] == 'K' or ss[-1] == 'K'):
            x += 1
        if(ss[0] == 'P' or ss[-1] == 'P'):
            x -= 1
    if(x >= 0):
        return 'K'
    return 'P'

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