import java.util.Scanner;

public class Minminzemi {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		String S = s.nextLine();
		s.close();
		int count = 0;
		while(S.length() != 0){
			int end = S.indexOf("n",0);
			count++;
			if(end != S.length()){
				S = S.substring(end+1);
			}else{
				break;
			}
		}
		System.out.println(count);

	}

}