//lr2.3
// CPP libs
#include <iostream>
#include <fstream>
#include <string>
#include <algorithm>
#include <memory>
#include <random>
//#include <vector>
//#include <stack>
//#include <exception>
//#include <stdexcept>

// C libs
#include <cmath>
#include <cctype>
#include <cstring>
#include <ctime>
//#include <cstdint>
//#include <cstdlib>
//#include <cstdio>
//#include <unistd.h>

using namespace std;

struct BinKor;

//Груз ::= Гирька | БинКор
struct Load {
    bool isWeight;
    union {
        int weight;
        BinKor* binKor;
    } data;
};

//Плечо ::= (Длина Груз)
struct Side {
    short length;
    Load* load;
};

//БинКор ::= (Плечо Плечо)
struct BinKor {
    Side* right;
    Side* left;
};

short Length (const BinKor bk) {
    short result = 0;
    if (bk.right) {
        result += bk.right->length;
        if (bk.right->load && !bk.right->load->isWeight) result += Length(*bk.right->load->data.binKor);
    }
    if (bk.left) {
        result += bk.left->length;
        if (bk.left->load && !bk.left->load->isWeight) result += Length(*bk.left->load->data.binKor);
    }
    return result;
}

//todo добавить ввод