a,b,c,d = map(int,input().split())
if d>=10:
    print('Impossible')
    exit()
else:
    print('Possible')
# B -> A
cnt = 0
res = 0
for (x,y) in zip([b,a],[50,100]):
    for i in range(x):
        cnt += 1
        res += 2**((cnt-1)//100) * y
print(res)