local n, m = io.read("*n", "*n")
local yes = "Possible"
local no = "Impossible"
if 4 <= m then
  -- m + (3-2-1) * others
  print(yes)
elseif m == 3 then
  -- n <= 5: 3 + (1+5-2-4) * others
  -- n == 4: (4-2-1)*3
  -- n == 3: (2-1)*3
  print(yes)
elseif m == 2 then
  -- n <= 4: 2 + (4-3-1) * others
  -- n == 3: 1+3-2
  -- n == 2: 1*2
  print(yes)
elseif m == 1 then
  -- n <= 5: 1 + (2+5-3-4) * others
  -- n == 4: 1*3+2-4
  -- n == 3: (2-1)*3
  -- n == 2: 2-1
  -- n == 1: 1
  print(yes)
else
  -- n <= 3: (3-2-1) * others
  print(3 <= n and yes or no)
end