x = []
while True:
    a = input('Введите латинское слово: ')
    if a == '':
        break
    else:
        if a.isalpha():
            if a[-3:] == 'ere' or a[-2:] in ['re', 'ri'] or a[-1] == 'i':
                x.append(a)

with open('words.txt', 'w', encoding='utf-8') as f:
    for s in x:
        f.write(s + '\n')