# No.745 letinopia raoha
a, b, c, d = [int(s) for s in input().split()]

if d < 10:
    print('Possible')

    score_total = 0
    combo = 1

    while combo <= a + b:
        if combo <= b:
            score_total += 50 * 2 ** ((combo - 1) // 100)
        elif b < combo <= a + b:
            score_total += 100 * 2 ** ((combo - 1) // 100) 
        print(combo, score_total)
        combo += 1

    print(score_total)
else:
    print('Impossible')