import sys
#sys.setrecursionlimit(10 ** 6)
#sys.set_int_max_str_digits(0)
INF = float('inf')
MOD = 10**9 + 7
MOD2 = 998244353
from collections import defaultdict
def ceil(A,B):
    return -(-A//B)
def solve():
    def II(): return int(sys.stdin.readline())
    def LI(): return list(map(int, sys.stdin.readline().split()))
    def LC(): return list(sys.stdin.readline().rstrip())
    def IC(): return [int(c) for c in sys.stdin.readline().rstrip()]
    def MI(): return map(int, sys.stdin.readline().split())
    H,S = input().split()
    H = int(H)
    S = int(S)
    if(abs(H-S)%2==0):
        print("Possible")
    else:
        print("Impossible")
    return
solve()