t = int(input())
for _ in range(t):
	n = int(input())
	a = input().split("-")
	pp, pk, kk = 0, 0, 0
	for i in a:
		if len(i) == 0:
			continue
		if i[0] == 'P' and i[-1] == 'P':
			pp += 1
		elif i[0] == 'K' and i[-1] == 'K':
			kk += 1
		else:
			pk += 1
	kk += (pk + 1) // 2
	pp += pk // 2
	if pk % 2 == 0:
		if kk >= pp:
			print("K")
		else:
			print("P")
	else:
		if kk > pp:
			print("K")
		else:
			print("P")