python解法
字符个数统计
http://www.nowcoder.com/questionTerminal/eb94f6a5b2ba49c6ac72d40b5ce95f50
ord函数输出ascii码的数值范围，
不在的not in
if name == 'main':
while True:
try:
s = raw_input()
i= 0
list = []
while i < len(s):
a = ord(s[i])
if a>=0 and a<= 127:
if s[i] not in list:
list.append(s[i])
# print s[i]
i = i+1
print len(list)
except:
- break
