# Combinatoric generator

# cat combgen
#!/usr/bin/python

# Combinatoric generator

from sys import argv
from itertools import combinations, permutations, product

f=argv[1]
r=int(argv[2])
n=argv[3::]

def doprint(r):
        for i in r:
                for j in i:
                        print j,
                print

def calc_combination(n,r):
        fr=1
        for i in range(0,r):
                fr=fr*(i+1)
        return calc_permutation(n,r)/fr

def calc_permutation(n,r):
        ln=len(n)
        lnr=ln-r
        fn=1
        for i in range(0,ln):
                fn=fn*(i+1)
        fnr=1
        for i in range(0,lnr):
                fnr=fnr*(i+1)
        return fn/fnr

def calc_product(n,r):
        ln=len(n)
        return ln**r

def help():
        print "Usage: combgen <combination|permutation|product> <r> <n>"

if      f == 'combination':
        print "Combinations = ",calc_combination(n,r)
        doprint(combinations(n,r))
elif    f == 'permutation':
        print "Permutations =",calc_permutation(n,r)
        doprint(permutations(n,r))
elif    f == 'product':
        print "Products =",calc_product(n,r)
        doprint(product(n,repeat=r))
else:
        help()