H, S = input().split()


def f(s):
    sgn = 1
    if s[0] == '-':
        sgn = -1
        s = s[1:]

    t = s[-10:]
    return int(t) * sgn



d = abs(f(H) - f(S))
if d % 2 == 0:
    print('Possible')
else:
    print('Impossible')