with open('file.txt') as f:
    a = f.read()
    a = a.replace('\n', '').replace('.', ' ')
    a = a.lower().split()

aa = []
for j in a:
    sl = ''
    count_aa = 0
    for i in j:
        if i.isalpha():
            sl += i
            count_aa += (i == 'a')
    if count_aa >= 2:
        if sl not in aa:
            aa += [sl]

print(*sorted(aa))