lofasz.py

#flip
def flip(n):
    print 1 - n

def flip2(n, m):
    
def sorted_union(list1,list2):
    list3 = [x for x in list1 if x in list2]
    return sorted(list(set(list3)))

def internal_permutation(number_digits, acc):
    if number_digits == 0:
        print acc
    else:        
        for i in range(10):
            internal_permutation(number_digits - 1, acc + '%d' % i)

def print_permutation(num_digits):
    internal_permutation(num_digits, '')

print_permutation(2)