n=input()
l=[]
for i in n:
if i!='{' and i!='}' and i!=',' and i!=" ":
l.append(i)
print(len(set(l)))#include<iostream>
#include<bits/stdc++.h>
using namespace std;
int main()
{
int count=0;
string s;
getline(cin,s);
sort(s.begin(),s.end());
for(int i=0; i<s.size()-1; i++)
{
if(s[i]=='{}' || s[i]==',' || s[i]==' ')
{
continue;
}
else
{
if(s[i]!=s[i+1])
{
count++;
}
}
}
cout<<count-1;
}Teddy and Tweety | Partitioning binary strings |
Special sets | Smallest chosen word |
Going to office | Color the boxes |
Missing numbers | Maximum sum |
13 Reasons Why | Friend's Relationship |
Health of a person | Divisibility |
A. Movement | Numbers in a matrix |
Sequences | Split houses |
Divisible | Three primes |
Coprimes | Cost of balloons |
One String No Trouble | Help Jarvis! |
Lift queries | Goki and his breakup |
Ali and Helping innocent people | Book of Potion making |
Duration | Birthday Party |
e-maze-in | Bricks Game |