#include <fstream>
#include <stack>
using namespace std;

bool hasPrecedence(char op1, char op2);
int processNextValues(stack<int> &valueStack, stack<char> &opStack);

int main()
{
    stack<int> valueStack;
    stack<char> opStack;
    char c;
    char lastRead = 'a';
    int nr;
    ifstream f("evaluare.in");
    bool firstRead = true;
    while (f >> c)
    {
        if (c == '-')
        {
            if (firstRead)
                c = 'u';
            else if (lastRead == '(')
                c = 'u';
            else if (lastRead == '+' || lastRead == '-' || lastRead == '*' || lastRead == '/')
                c = 'u';
        }

        if (c >= '0' && c <= '9')
        {
            if (lastRead >= '0' && lastRead <= '9')
            {
                nr = valueStack.top(), valueStack.pop();
                nr = nr * 10 + (c - '0');
                valueStack.push(nr);
            }
            else
                valueStack.push(c - '0');
        }
        else if (c == '(' || c == 'u')
            opStack.push(c);
        else if (c == '*' || c == '/' || c == '+' || c == '-')
        {
            while (!opStack.empty() && hasPrecedence(opStack.top(), c))
                valueStack.push(processNextValues(valueStack, opStack));
            opStack.push(c);
        }
        else if (c == ')')
        {
            while (opStack.top() != '(')
                valueStack.push(processNextValues(valueStack, opStack));
            opStack.pop();
            if (!opStack.empty() && opStack.top() == 'u')
            {
                nr = valueStack.top(), valueStack.pop();
                valueStack.push(-nr);
                opStack.pop();
            }
        }
        lastRead = c;
        firstRead = false;
    }
    f.close();

    while (!opStack.empty())
        valueStack.push(processNextValues(valueStack, opStack));

    ofstream g("evaluare.out");
    g<< valueStack.top();
    g.close();

    return 0;
}

bool hasPrecedence(char op1, char op2)
{
    if (op1 == 'u')
        return true;
    else if (op1 == '(')
        return false;
    else if ((op1 == '+' || op1 == '-') && (op2 == '*' || op2 == '/'))
        return false;

    return true;
}

int processNextValues(stack<int> &valueStack, stack<char> &opStack)
{
    char sign = opStack.top();
    opStack.pop();
    int operand2 = valueStack.top();
    valueStack.pop();
    if (sign == 'u')
        return -operand2;

    int operand1 = valueStack.top();
    valueStack.pop();

    switch (sign)
    {
        case '+':
            return operand1 + operand2;
        case '-':
            return operand1 - operand2;
        case '*':
            return operand1 * operand2;
        case '/':
            return operand1 / operand2;
    }
}