perfect, great, good, miss = [int(x) for x in input().split(' ')]

if miss >= 10:
    print('Impossible')

else:
    combo = perfect + great
    point = 0
    for i in range(combo):
        bounus = 2 ** (i // 100)
        if (i + 1) <= great:
            point += 50 * bounus
        else:
            point += 100 * bounus
            
    print('Possible')
    print(point)