Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.


-----Input-----

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.


-----Output-----

Print a single number — the number of distinct letters in Anton's set.


-----Examples-----
Input
{a, b, c}

Output
3

Input
{b, a, b, a}

Output
2

Input
{}

Output
0

Difficulty: interview

Starter code:

Solutions:
s = input()

s = s[1: -1].replace(',', '')

result = set(s.split())

print(len(result))


a = input().strip()
s = set()
for i in a:
    if i not in ' {},':
        s.add(i)
        
print(len(s))

ans = set()

for c in input():
    if c in 'abcdefghijklmnopqrstuvwxyz':
        ans.add(c)

print(len(ans))

3

import sys

line = sys.stdin.readline()
s = set()
for c in line:
    if 'a' <= c <= 'z':
        s.add(c)
print(len(s))


s = set()
string = input().rstrip()
i = 1
while i < len(string):
    s.add(string[i])
    i += 3
if string == "{}":
    print(0)
else:
    print(len(s))

sa=input()
if sa=="{}":
    print(0)
else:
    sa2=[]
    for x in range(1, len(sa), 3):
        sa2.append(sa[x])
    sa3=list(set(sa2))
    print(len(sa3))


# -*- coding: utf-8 -*-
import sys
f = sys.stdin
St = f.readline().strip()

letters = {}
for s in St:
    if s not in '{, }':
        if s not in letters:
            letters[s] = 1

print(len(letters))

a = input()
if len(a) == 2:
    print(0)
else:
    a = a.split(', ')
    a[0] = a[0][1:]
    a[-1] = a[-1][:1]
    print(len(set(a)))

n=set(input())
n=len(n)
if n>3:
    print(n-4)
elif n==3:
    print(1)
else:
    print(0)


s = input()[1:-1]
if len(s) == 0:
    print(0)
else:
    print(len(set(s.split(', '))))

import sys





def main():
	data = sys.stdin.readline().strip()[1:-1]
	datax = data.split(', ')
	datas = set(datax)
	if datax == ['']:
		print(0)
	else:
		print(len(datas))





main()






from sys import stdin as cin
from math import factorial as f
from itertools import combinations as comb
from collections import Counter as C

s = input()
s=s[1:]
n = len(s)
s = s[:n-1]

m = list(s.split(', '))
if m==['']:
    print(0)
else:

    #print(m,len(m))
    r = C(m)
    print(len(list(r)))


#!/usr/bin/env python3
# -*- coding: utf-8 -*-
used = []
a = input().replace("{","").replace("}","").replace(" ","").split(",")
if a == [""]:
	print("0")
else:
	for b in a:
		if b not in used:
			used.append(b)
	print(len(used))


s = input()
if s == '{}':
    c = set()
else:
    c = set(s[1:len(s)-1].split(', '))
print(len(c))

import sys


def main(stdin):
    return len(set([e for e in stdin[0][1:-1].split(', ') if e != '']))


def __starting_point():
    skip_first_line = False
    stdin = [ln for ln in [ln.rstrip() for ln in sys.stdin.readlines()[1 if skip_first_line else 0:]] if len(ln) > 0]
    print(main(stdin))

__starting_point()

s = input()

if s == '{}':
    print(0)
else:
    print(len(set(s.strip('}{').split(', '))))

a = set(input()[1:-1].split(', '))
if '' in a:
    print(0)
else:
    print(len(a))


st=input()[1:-1].split(', ')
if len(st[0])!=0:
    print(len(set(st)))
else:
    print(0)

x=input()
list=x.split()
list2=[]
if list[0][1]=="}":
    list2=[]
else:
    list2.append(list[0][1])
i=1
while i < len(list):
    list2.append(list[i][0])
    i+=1
list3=[]
for item2 in list2:
    if item2 not in list3:
        list3.append(item2)
print(len(list3))


inp = input()

res = [0 for i in range(30)]

for c in inp:
    if ord('a') <= ord(c) <= ord('z'):
        res[ord(c) - ord('a')] = 1

print(sum(res))

s=input()
s=s[1:-1]
if s=="":
    print ("0")
else:
    a=s.split(", ")
    print(len(set(a)))
    


print(len(set(s for s in input()[1:-1].split(", ") if s != "")))

print(len(set([x for x in input() if 123>ord(x)>44])))