题解 | #字符个数统计#
字符个数统计
https://www.nowcoder.com/practice/eb94f6a5b2ba49c6ac72d40b5ce95f50
n=input()
num=[]
for i in range(len(n)):
if n[i:i+1] in num:
continue
else:
num.append(n[i:i+1])
str_num = ''.join(map(str,num))
print(len(str_num))