h,s = map(int,input().split())
import sys
sys.setrecursionlimit(5*10**5)
input = sys.stdin.readline
sys.set_int_max_str_digits(0)
from collections import defaultdict, deque, Counter
from heapq import heappop, heappush
from bisect import bisect_left, bisect_right
from math import gcd, lcm, factorial, perm, comb
from itertools import product, permutations
#重複あり：list(product(list('123'),repeat = 2)),重複なし：list(permutations(list('123')))
MOD = 998244353

if h%2 == s%2:
    print('Possible')
else:
    print('Impossible')