import sys
sys.setrecursionlimit(5*10**5)
input = sys.stdin.readline
from collections import defaultdict, deque, Counter
from heapq import heappop, heappush
from bisect import bisect_left, bisect_right
from math import gcd


n,m = map(int,input().split())

if (n-m)%2== 0:
    print("Possible")
else:
    print("Impossible")