#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <math.h>
#include <cmath>
#include <limits.h>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <functional>
#include <stdio.h>
using namespace std;

long long MOD = 1000000007;

int func( string s ) {
    int ret = 0;
    queue<char> c;
    for ( int i = 0; i < s.length(); i++ ) {
        if ( isdigit(s[i]) ) {
            string t;
            while ( isdigit( s[i] ) ) {
                t += s[i];
                i++;
            }
            i--;
            int a = stoi(t);
            while ( !c.empty() ) {
                a = c.front() == '+' ? a : -a;
                c.pop();
            }
            ret += a;
        }
        else {
            c.push(s[i]);
        }
    }
    return ret;
}

int main() {
    
    string S;
    cin >> S;
    bool b = false;
    for ( int i = 0; i < S.length(); i++ ) {
        if ( isdigit(S[i]) ) { b = true; }
        else if ( b ) { S[i] = S[i] == '+' ? '-' : '+'; break; }
    }
    cout << func( S ) << endl;

    return 0;
}