public class Solution {
    public static void main(String[] args) {
        try
        {
            BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
            String fileName = reader.readLine();
            reader.close();
            reader = new BufferedReader(new FileReader(fileName));
            int count = 0;
            while(reader.ready())
            {
                String[] input = reader.readLine().split(" ");
                for (String s : input)
                {
                    if(s.matches("^world\\p{Punct}*"))
                        count++;
                }
            }
            System.out.println(count);
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
}