import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.regex.*;

public class Main {
	private static FileReader in;
	private static FileWriter out;
	private static BufferedReader bufferedReader;
	
	public static void main(String[] args) {
		try {
			int letters = 0;
			int words = 0;
			in = new FileReader("./text.in");
			out = new FileWriter("./text.out");
			bufferedReader = new BufferedReader(in);
			String s = bufferedReader.readLine();
			Pattern pattern = Pattern.compile("[a-zA-Z]+");
			Matcher matcher = pattern.matcher(s);
			while(matcher.find()) {
				if(matcher.group().length() != 0) {
					letters += matcher.group().length();
					words++;
				}
			}
			int average = letters / words;
			out.write(Integer.toString(average));
			bufferedReader.close();
			out.close();
			in.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}