#include<iostream>
using namespace std;
int main(){
bool table[34] = {0, }; // (0 ~ 25 : a ~ z), (26 ~ 33 : c= ~ z=)
char str[102];
int counter = 0;
cin >> str;
while( !((int) str[counter] == 0) ){
cout << counter <<" 번째 문자 보는중" << endl;
if(str[counter] == 'c'){
if(str[counter + 1] == '='){
table[26] = 1;
counter++;
}
else if(str[counter + 1] == '-'){
table[27] = 1;
counter++;
}
else{
table[2] = 1;
}
} // end of case 'c'
else if(str[counter] == 'l'){
if(str[counter + 1] == 'j'){
table[30] = 1;
counter++;
}
else{
table[11] = 1;
}
} // end of case 'l'
else if(str[counter] == 'n'){
if(str[counter + 1] == 'j'){
table[31] = 1;
counter++;
}
else{
table[13] = 1;
}
} // end of case 'n'
else if(str[counter] == 's'){
if(str[counter + 1] == '='){
table[32] = 1;
counter++;
}
else{
table[18] = 1;
}
} // end of case 's'
else if(str[counter] == 'd'){
if(str[counter + 1] == '-'){
table[29] = 1;
counter++;
}
else if( (str[counter + 1] == 'z') && (str[counter + 2] == '=') ){
table[28] = 2;
counter =+ 2;
}
else{
table[3] = 1;
}
} // end of case 'd'
else if(str[counter] == 'z'){
if(str[counter + 1] == '='){
table[33] = 1;
counter++;
}
else{
table[25] = 1;
}
} // end of case 'z'
else{
table[(int)str[counter] - 97] = 1;
} // end of normal alphab
counter++;
} // end of while
counter = 0;
for(int c = 0; c < 34; c++){
if(table[c]) counter++;
}
/* DEBUG
for(int t = 0; t < 34; t++){
cout << "(" << t << ", " << table[t] << ")" << endl;
}
*/
cout << counter << endl;
return 0;
}