#include <bits/stdc++.h>
using namespace std;
map<string,double> ch;
string s;
double cnt(int st)
{
    double ans=0,p=0;
    int i=st;
    while(s[i]!=')'&&i<s.size())
    {
        if(s[i]>='A'&&s[i]<='Z')
        {
        	ans+=p;
            p=ch[s.substr(i,1+(s[i+1]>='a'&&s[i+1]<='z'))];
            i+=1+(s[i+1]>='a'&&s[i+1]<='z');
            continue;
        }
        if(s[i]=='(')
        {
            ans+=p;
            int j=i+1;
            while(s[j]!=')')
            	j++;
            p=cnt(i+1);
            i=j+1;
            continue;
        }
        if(s[i]>='0'&&s[i]<='9')
        {
        	double mul=0;
        	while(s[i]>='0'&&s[i]<='9')
        	{
        		mul=mul*10+s[i]-'0';
        		i++;
			}
			p*=mul;
		}
        if(s[i]=='~')
        {
        	if(s[i+1]=='H')
        		ans+=18;
        	else
        		ans+=(s[i+1]-'0')*18;
        	break;
		}
		i++;
    }
    return ans+p;
}
int main()
{
    ch["H"]=1;
    ch["C"]=12;
    ch["N"]=14;
    ch["O"]=16;
    ch["F"]=19;
    ch["Na"]=23;
    ch["Mg"]=24;
    ch["Al"]=27;
    ch["Si"]=28;
    ch["P"]=31;
    ch["S"]=32;
    ch["Cl"]=35.5;
    ch["K"]=39;
    ch["Ca"]=40;
    ch["Mn"]=55;
    ch["Fe"]=56;
    ch["Cu"]=64;
    ch["Zn"]=65;
    ch["Ag"]=108;
    ch["I"]=127;
    ch["Ba"]=137;
    ch["Hf"]=178.5;
    ch["Pt"]=195;
    ch["Au"]=197;
    ch["Hg"]=201;
    cin>>s;
    cout<<cnt(0)<<endl;
    return 0;
}