a = io.read("*line")
nlist = {}
j = 1

for i in a:gmatch("%S+") do
    nlist[j] = tonumber(i)
    j = j + 1
end
arg1 = nlist[1]
arg2 = nlist[2]
     
if (arg1+arg2) % 3 == 0.0 then
    print('Possible')
else
    print('Impossible')
end