// Problem: P4711 「化学」相对分子质量
// Contest: Luogu
// URL: https://www.luogu.com.cn/problem/P4711
// Memory Limit: 125 MB
// Time Limit: 1000 ms
//
// Powered by CP Editor (https://cpeditor.org)

#include <cstring>
#include <iostream>
#include <map>

using namespace std;

const int maxn = 1e6 + 10;

char str[maxn];
int len, H2O = 18;
double ans;
map<string, double> s;

double get_ans(int l, int r)
{
    double res = 0;
    for (int i = l; i <= r;) {
        if (str[i] == '(') {
            int j = i + 1;
            for (; j <= r; j++)
                if (str[j] == ')')
                    break;
            double tmp = get_ans(i + 1, j - 1);
            if (str[j + 1] == '_') {
                int num = -1;
                for (j = j + 3; j <= r; j++) {
                    if (str[j] == '}')
                        break;
                    if (num == -1)
                        num = 0;
                    num = num * 10 + (str[j] - '0');
                }
                res += 1.0 * (num == -1 ? 1 : num) * tmp;
            } else {
                res += tmp;
            }
            i = j + 1;
        } else if (str[i] != ')') {
            int j = i + 1;
            string ele = "";
            ele += str[i];
            for (; j <= r; j++) {
                if ((str[j] >= 'A' && str[j] <= 'Z') || str[j] == '_' || str[j] == '(')
                    break;
                ele += str[j];
            }
            if (str[j] == '_') {
                int num = -1;
                for (j = j + 2; j <= r; j++) {
                    if (str[j] == '}')
                        break;
                    if (num == -1)
                        num = 0;
                    num = num * 10 + (str[j] - '0');
                }
                res += 1.0 * (num == -1 ? 1 : num) * s[ele];
                i = j + 1;
            } else
                res += 1.0 * s[ele], i = j;
        }
    }
    return res;
}

int main()
{
    s["H"] = 1;
    s["C"] = 12;
    s["N"] = 14;
    s["O"] = 16;
    s["F"] = 19;
    s["Na"] = 23;
    s["Mg"] = 24;
    s["Al"] = 27;
    s["Sl"] = 28;
    s["P"] = 31;
    s["S"] = 32;
    s["Cl"] = 35.5;
    s["K"] = 39;
    s["Ca"] = 40;
    s["Mn"] = 55;
    s["Fe"] = 56;
    s["Cu"] = 64;
    s["Zn"] = 65;
    s["Ag"] = 108;
    s["I"] = 127;
    s["Ba"] = 137;
    s["Hf"] = 178.5;
    s["Pt"] = 195;
    s["Au"] = 197;
    s["Hg"] = 201;

    cin >> (str + 1);
    len = strlen(str + 1);
    for (int i = 1; i <= len; i++) {
        if (str[i] == '~') {
            int num = -1;
            for (int j = i + 1; j <= len - 6; j++) {
                if (num == -1)
                    num = 0;
                num = num * 10 + (str[j] - '0');
            }
            ans += 1.0 * H2O * (num == -1 ? 1 : num);
            ans += 1.0 * get_ans(1, i - 1);
            break;
        }
    }
    if (ans)
        cout << ans << "\n";
    else {
        ans = get_ans(1, len);
        cout << ans << "\n";
    }
    return 0;
}

我知道我菜。别骂了。