T = int(input())
for _ in range(T):
  N = int(input())
  S = input()
  P,K,T = 0,0,0
  f,s,g = 0,0,0
  for i in range(N):
    if f == 0:
      if S[i] != '-':
        if S[i] == 'P':
          s = 1
          g = 1
        else:
          s = 2
          g = 2
        f = 1
    else:
      if S[i] == '-':
        if s == g:
          if s == 1:
            P += 1
          else:
            K += 1
        else:
          T += 1
        f = 0
      elif S[i] == 'P':
        g = 1
      else:
        g = 2
  if f:
    if s != g:
      T += 1
    else:
      if s == 1:
        P += 1
      else:
        K += 1
  if K >= P:
    print('K')
  else:
    print('P')