题解 | #字符个数统计#
字符个数统计
https://www.nowcoder.com/practice/eb94f6a5b2ba49c6ac72d40b5ce95f50
# 20240910
def f(s):
a = ''
for i in s:
if 0 <= ord(i) <= 127:
if i not in a:
a += i
return a
s = input()
print(len(f(s)))
