A, B, C, D = map(int, input().split())

life_remaining = 1000 - 100 * D

if life_remaining <= 0:
    print("Impossible")
else:
    total = A + B
    score = 0
    for i in range(1, total + 1):
        k = (i - 1) // 100
        multiplier = 2 ** k
        if i <= B:
            score += 50 * multiplier
        else:
            score += 100 * multiplier
    print("Possible")
    print(score)