#include <iostream>

using namespace std;

string s;
int x, y, ans;

int main() {
    cin >> s;
    ans = 0, x = y = 1;
    for (int i = 0; i < s.size(); ++i) {
        if ('0' <= s[i] && s[i] <= '9') {
            ans += x * y * (s[i] - '0');
        } else if (s[i] == '-') {
            if (x == -1) y = -1;
            else x = -1, y = 1;
        } else if (s[i] == ')') {
            x = y = 1;
        }
    }
    printf("%d\n", ans);

    return 0;
}