#include <iostream>

#include <string>

using namespace std;

int num (char str) {
	
	if(str>=48&&str<=122) return 1;
	
	return 0;
}

int main () {
	
	int nun;
	
	string str;
	
	getline(cin,str);
	
	for (int i = 0; i<=str.size(); i++) nun=nun+num(str [i]);
	
	cout<<nun;
	
	return 0;
}