#include <iostream>
#include <string>
#include <set>
using namespace std;
int main() {
string str;
getline(cin, str);
set<char> chars;
for(char c : str) {
if((unsigned char)c <= 127) { // 检查ASCII范围
chars.insert(c);
}
}
cout << chars.size() << endl;
return 0;
}
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String str = sc.nextLine();
HashSet<Character> chars = new HashSet<>();
for(char c : str.toCharArray()) {
if(c <= 127) { // 检查ASCII范围
chars.add(c);
}
}
System.out.println(chars.size());
}
}
s = input()
chars = set()
for c in s:
# ord()函数返回字符的ASCII值
if ord(c) <= 127:
chars.add(c)
print(len(chars))