#include <iostream>
using namespace std;

int main(){
	string S;
	cin >> S;
	int ans = 0;
	bool if_minus = false;
	bool if_in_minus_bracket = false;
	for(int i = 0; i < S.size(); i++){
		if('0' <= S[i] && S[i] <= '9'){
			if((if_minus + if_in_minus_bracket) % 2){
				ans -= S[i] - '0';
			}else{
				ans += S[i] - '0';
			}
			if_minus = false;
		}else if(S[i] == '-'){
			if_minus = true;
		}else if(S[i] == '('){
			if(if_minus){
				if_in_minus_bracket = true;
			}
			if_minus = false;
		}else if(S[i] == ')'){
			if_in_minus_bracket = false;
		}
	}
	cout << ans << endl;
}