#include <iostream>
#include <map>
using namespace std;

map<string, double> table;

enum Token_value {
    NAME,   NUMBER, END,
    PLUS='+', MINUS='-', MUL='*', DIV='/',
    PRINT=';', ASSIGN='=',  LP='(', RP=')'
};

Token_value curr_tok = PRINT;

int no_of_errors;

double error(const string& s)
{
    no_of_errors++;
    cerr << "error: " << s << '\n';
    return 1;
}
double term(bool);
double prim(bool);
Token_value get_token();

double expr(bool get)  //add and subtract
{
    double left = term(get);
    for(;;)   // forever
    switch(curr_tok) {
    case PLUS:
        left += term(true);
        break;
    case MINUS:
        left -= term(true);
        break;
    default:
        return left;
    }
}

double term(bool get)   // multiply and divide
{
    double left = prim(get);
    for(;;)
    switch(curr_tok) {
    case MUL:
        left *= prim(true);
        break;
    case DIV:
        if(double d = prim(true)) {
            left /= d;
            break;
        }
        return error("divide by 0");
    default:
        return left;
    }
}

double number_value;
string string_value;
double prim(bool get)   // handle primaries
{
    if(get) get_token();
    switch(curr_tok) {
    case NUMBER:  //floating point const
    {
        double v = number_value;
        get_token();
        return v;
    }
    case NAME:
    {
        double& v = table[string_value];
        if(get_token()==ASSIGN) v = expr(true);
        return v;
    }
    case MINUS:
        return -prim(true);
    case LP:
    {
        double e = expr(true);
        if(curr_tok != RP) return error(") expected");
        get_token();      // eat ')'
        return e;
    }
    default:
        return error("primary expected");
    }
}

Token_value get_token()
{
    char ch = 0;
    //cin>>ch;
    do { //skip whitespace except '\n'
        if(!cin.get(ch)) return curr_tok = END;
    } while (ch!='\n' && isspace(ch));
    switch(ch){
    case 0:
        return curr_tok=END;  // assign and return
    case ';':
    case '\n':
        return curr_tok = PRINT;
    case '*':
    case '/':
    case '+':
    case '-':
    case '(':
    case ')':
    case '=':
        return curr_tok = Token_value(ch);
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9': case '.':
        cin.putback(ch);
        cin >> number_value;
        return curr_tok = NUMBER;
    default:    //NAME, NAME =, or error
        if(isalpha(ch)) {
            //cin.putback(ch);
            //cin>>string_value;
            string_value = ch;
            while(cin.get(ch) && isalnum(ch))
                string_value.push_back(ch);
            cin.putback(ch);
            return curr_tok=NAME;
        }
        error("bad token");
        return curr_tok=PRINT;
    }
}

int main()
{
    //cout << static_cast<int>('-');
    table["pi"] = 3.1415926535897932385;
    table["e"] = 2.7182818284590452354;
    while(cin) {
        get_token();
        if(curr_tok == END) break;
        if(curr_tok == PRINT) continue;
        cout << expr(false) << '\n';
    }
    return no_of_errors;
}