I,R=input,range
for t in R(int(I())):
	N,S,c=int(I()),I()+'-','-'
	K=P=0
	for i in R(N):
		if S[i]>'-':
			if c<'K':c=S[i]
			if S[i+1]<'K':
				if c==S[i]:
					if c>'K':P+=1
					else:K+=1
				c='-'
	print("KP"[P>K])