import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String S = sc.nextLine();
        int a = 0;
        int c = 0;
        while(true){
            a = S.indexOf("n");
            S = S.substring(a+1);
            if(a==-1){
                break;
            }
            c++;
        }
        System.out.println(c);
    }
}