a, b, c, d = map(int, input().split())

if 10 <= d:
    print("Impossible")
else:
    ans = 0
    print("Possible")
    for i in range(a + b):
        if b > 0:
            b -= 1
            ans += 50 * 2 ** (i // 100)
        else:
            ans += 100 * 2 ** (i // 100)
    print(ans)