题解 | #字符个数统计#

import sys
import re

def statistics(str):
    # 字符串去空格   
    # 字符串检查ASCII码范围
    # 字符串去重
    l_result = []
    for c in str:
        if c != '\n' and c not in l_result:
            l_result.append(c)
    # 统计长度
    return len(l_result)


if __name__ == '__main__':
    str = sys.stdin.readline().strip()
    result = statistics(str)
    print(result)