import java.io.*;

/**
 * Created by EugeniaKim on 14/12/2015.
 */
public class Main {

    private static int character;
    private static int word;
    private static final char SPACE = ' ';

    public static void getAverage(String inputFileName, String outputFileName) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader(inputFileName));
        int current = br.read();
        while(current != -1) {
            if(Character.isAlphabetic(current)) {
                character++;
            }
            if((char) current == SPACE) {
                word++;
            }
            current = br.read();
        }
        word++;
        BufferedWriter bw = new BufferedWriter(new FileWriter(outputFileName));
        bw.write(String.valueOf(character/word));
        br.close();
        bw.close();
    }

    public static void main(String[] args) throws IOException {
        getAverage("text.in", "text.out");
    }
}