#include <bits/stdc++.h>
#define REP(i, a, n) for(ll i = ((ll) a); i < ((ll) n); i++)
using namespace std;
typedef long long ll;

string S;
ll p = 0;

ll dfs() {
  ll ret = S[p++] - '0';
  while(p < S.length() && S[p] != ')') {
    char op = S[p++];
    ll x;
    if(S[p] == '(') {
      p++;
      x = dfs();
      p++;
    } else {
      x = S[p] - '0';
      p++;
    }
    if(op == '+') ret += x;
    if(op == '-') ret -= x;
  }
  return ret;
}

int main(void) {
  cin >> S;
  cout << dfs() << endl;
}