using System;
using System.Collections.Generic;
using System.Linq;

class Magatro {
    
    static void Main() {
        string s = Console.ReadLine();
        s = s.Replace("-","");
        Console.WriteLine(cnt(s));
    }
    static int cnt(string s) {
        string st = s.Replace("m", "");
        return s.Length - st.Length;
    }

}