题解 | #字符个数统计#

strs = input()

def unique_counts(strs: str) -> int:
    hash_table = {}

    for sub in strs:
        if not hash_table.get(sub):
            hash_table.setdefault(sub, 1)
        else:
            hash_table[sub] += 1
    return len(hash_table)

print(unique_counts(strs))