import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;

/**
-Lasa-mainpace,caaminvatatazinoaptetoataziua!
 * Created by slycer on 9/6/15.
 */
public class Main {


    public static void main(String[] args) throws IOException {
        Scanner in = new Scanner(new FileInputStream("text.in"));
        PrintWriter out = new PrintWriter("text.out");
        String line = in.nextLine().toLowerCase() +  " " ;

        int numarCuvinte = 0;
        int numarCaractere = 0;
        int partialCount = 0;
        for ( int i=0; i<line.length(); i++ ){
            if ( 'a'<= line.charAt(i) && line.charAt(i) <= 'z' ){
                partialCount ++;
            } else {
                if ( partialCount > 0 ){
                    numarCuvinte ++;
                    numarCaractere += partialCount;
                    partialCount = 0;
                }
            }
        }


        if ( numarCuvinte == 0 ){
            out.print( 0 );
        } else {
            out.print(numarCaractere / numarCuvinte);
        }
        out.close();;
    }

}