def output_format_one(first, middle, last):
    _format = "{0}, {1}.".format(last, first[0])
    return _format

def output_format_two(first, middle, last):
    _format = "{0}, {1}.{2}.".format(last, first[0], middle[0])
    return _format

if __name__ == '__main__':
    name = input("Input your name: ")

    name = name.split(' ')

    if len(name) == 2:
        name = output_format_one(name[0], None, name[1])
    elif len(name) == 3:
        name = output_format_two(name[0], name[1], name[2])

    print(name)