import sys

p = sys.stdin.readline().strip()

Onlynum = set(p)

count = 0

for i in Onlynum:
    if 0 <= ord(i) <= 127:
        count += 1

print(count)

有点习惯性想多了，一开始还想着建个集合挨个查重，结果后面一想，又不需要顺序，我直接去重不行吗....