Chairs

#!usr/local/bin/python3.8
# -*- coding: utf-8 -*import

names_input = input().split(', ')
chairs_count = int(input())


def combinations(names, chairs, comb=[]):
    if len(comb) == chairs:
        print(', '.join(comb))
        return
    for i in range(len(names)):
        x = names[i]
        comb.append(x)
        combinations(names[i + 1:], chairs, comb)
        comb.pop()


combinations(names_input, chairs_count)