from typing_extensions import Annotated
T=int(input())


for i in range(T):
  w=g=r=0
  t=True
  S=list(map(int,input().split()))
  for j in range(len(S)):
    if not w>=g>=r:
      print("imporssible")
      t=False
      break
    if S[j]=="W":
      w+=1
    if S[j]=="G":
      g+=1
    if S[j]=="R":
      r+=1
  if g==r and t:
    print("possible")
  else:
    print("impossible")