import java.io.BufferedReader;

import java.io.FileReader;
import java.io.InputStreamReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Solution {
    public static void main(String[] args) throws Exception {

BufferedReader reade    = new BufferedReader(new InputStreamReader(System.in));

        String s = reade.readLine();

        reade.close();


        FileReader fe = new FileReader(s);
        BufferedReader reader = new BufferedReader(fe);

        Pattern pattern = Pattern.compile("\\bworld\\b");
        String ss ;
        int i = 0;
        Matcher matcher;
        while ((ss = reader.readLine()) != null) {


            matcher = pattern.matcher(ss);
            while (matcher.find()){
                i++;

            }
        }

        System.out.println(i);

        fe.close();
        reader.close();





    }
}