#!/usr/bin/env lua

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 then
        print('Possible')
else
        print('Impossible')
end
