import java.io.*;

class Asaear {
    String op;
    int    val;
    Asaear sabg;
    Asaear sabd;

    Asaear (String o, int v, Asaear g, Asaear d) {
        op = o;
        val = v;
        sabg = g;
        sabd = d;
    }
}

public class CodeTd7 {

    public static String Lire () {
        BufferedReader in = 
            new BufferedReader(new InputStreamReader(System.in));
        String s;
        try { s = in.readLine(); }
        catch (IOException e) { s = "echec"; }
        return(s);
    }

    static Asaear construit() {
        return(new Asaear("x", -1, 
                          new Asaear("+", -1, 
                                     new Asaear("feuille", 3, null, null), 
                                     new Asaear("feuille", 4, null, null)),
                          new Asaear("feuille", 5, null, null)));
    }     

    static int f (Asaear b) {
        if (b == null) 
            return(0);
        else
            if (b.op.equals("feuille")) 
                return(0);
            else
                return(1 + f(b.sabg) + f(b.sabd));
    }

    public static void main (String[] args) {
        Asaear a;
        a = construit();
        System.out.println(f(a));
    }
}