[Code] python in C# umschreiben

valid_input = False
while(not valid_input):
 ns = raw_input("n = ")
 try:
 n = int(ns)
 valid_input = True
 except ValueError:
 print ns + " is not a valid integer!"
 pass

used_numbers = [0]
clock = []
for i in range(n):
 clock.append(0)
 used_numbers.append(2**n - 2**i)

def number(cur, bit):
 ret = bit
 exp = n - 1
 for i in cur:
 ret += i * 2**exp
 exp -= 1
 return ret

tried_low = False
while len(clock) < 2**n - n:
 cur = clock[-n+1:]
 if not tried_low:
 curnum = number(cur, 0)
 if not curnum in used_numbers:
 clock.append(0)
 used_numbers.append(curnum)
 else:
 tried_low = True
 else:
 curnum = number(cur, 1)
 if not curnum in used_numbers:
 clock.append(1)
 used_numbers.append(curnum)
 tried_low = False
 else:
 bit = clock.pop()
 used_numbers.remove(number(clock[-n+1:], bit))
 while (bit == 1):
 bit = clock.pop()
 used_numbers.remove(number(clock[-n+1:], bit))
 tried_low = True

for i in range(n):
 clock.append(1)

print clock