import sys
input=lambda: sys.stdin.readline().rstrip()
a,b,c,d=map(int,input().split())
if d>=10:
  print("Impossible")
else:
  print("Possible")
  ans=0
  ct=1
  while a+b>0:
    mul=2**((ct-1)//100)
    if b>0:
      ans+=50*mul
      b-=1
    else:
      ans+=100*mul
      a-=1
    ct+=1
  print(ans)