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

def addScore(total, combo, score):
    rate = 2**math.floor(combo/100)
    total += score * rate
    combo += 1

    return total, combo

if d == 10:
    print('Impossible')
else:
    combo = 0
    total = 0
    for i in range(b):
        total,combo = addScore(total, combo, 50)

    for i in range(a):
        total,combo = addScore(total, combo, 100)

    print('Possible')
    print(total)