#include <iostream>
#include <string>
#include <stack>
using namespace std;

int main(int argc, char* argv[])
{
	string S;
	cin>>S;
	char ch;
	char op;
	char data1,data2;
	stack<char> St;
	int i;
	for (i=0;i<S.length();i++){
		ch=S[i];
		if (ch=='+' || ch == '-'){
			St.push(ch);
			continue;
		}else if (ch=='('){
			St.push(ch);
			continue;
		}else if (ch==')'){
			ch=St.top();
			St.pop();
			St.pop();
			op=St.top();
			St.pop();
			data1=St.top();
			St.pop();
			switch(op){
				case '+':
					St.push(data1-'0'+ch-'0'+'0');
					break;
				case '-':
					St.push((data1-'0')-(ch-'0')+'0');
					break;
			}
			continue;
		}
		if ((ch>='0' && ch<='9')){
			if (St.empty()){
				St.push(ch);
				continue;
			}
			char op=St.top();
			if (op=='+' || op=='-'){
				St.pop();
				data1=St.top();
				St.pop();
				switch(op){
					case '+':
						St.push(data1-'0'+ch-'0'+'0');
						break;
					case '-':
						St.push((data1-'0')-(ch-'0')+'0');
						break;
				}
			}else{
				St.push(ch);
			}
		}
	}
	while (!St.empty()){
		data2=St.top();
		St.pop();
		if (St.empty()){
			cout<<data2<<endl;
			return 0;
		}
		op=St.top();
		St.pop();
		data1=St.top();
		St.pop();
		switch(op){
			case '+':
				St.push(data1-'0'+data2-'0'+'0');
				break;
			case '-':
				St.push((data1-'0')-(data2-'0')+'0');
				break;
		}
	}
	return 0;
}