#include <stdio.h>
#include <cmath>
#include <algorithm>
#include <cfloat>
#include <stack>
#include <queue>
#include <vector>
#include <string>
#include <iostream>
#include <set>
#include <map>
#include <time.h>
typedef long long int ll;
typedef unsigned long long int ull;
#define BIG_NUM 2000000000
#define MOD 1000000007
#define EPS 0.000000001
using namespace std;

#define NUM 200

enum Type{
	MAX,
	MIN,
};

char buf[NUM+5];
int dp[NUM][NUM][2];
int num_count,op_count;
int num_loc[NUM],op_loc[NUM];

bool is_digit(char ch){
	return ch >= '0' && ch <= '9';
}

bool is_op(char ch){
	return ch == '+' || ch == '-';
}


int main(){

	scanf("%s",buf);

	num_count = 0,op_count = 0;
	for(int i = 0; buf[i] != '\0'; i++){
		if(is_digit(buf[i])){
			num_loc[num_count++] = i;
		}else if(is_op(buf[i])){
			op_loc[op_count++] = i;
		}
	}

	for(int left = 0; left < num_count; left++){
		dp[left][left][MAX] = buf[num_loc[left]]-'0';
		dp[left][left][MIN] = buf[num_loc[left]]-'0';
		for(int right = left+1; right < num_count; right++){
			dp[left][right][MAX] = -BIG_NUM;
			dp[left][right][MIN] = BIG_NUM;
		}
	}

	int right,left_left,left_right,right_left,right_right;

	for(int length = 2; length <= num_count; length++){
		for(int left = 0; left+length-1 < num_count; left++){
			right = left+length-1;

			for(int op = left; op < right; op++){
				left_left = left;
				left_right = op;

				right_left = op+1;
				right_right = right;

				if(left_left != left_right && (buf[num_loc[left_left]+1] == ')' || buf[num_loc[left_right]-1] == '('))continue;
				if(right_left != right_right && (buf[num_loc[right_left]+1] == ')' || buf[num_loc[right_right]-1] == '('))continue;

				if(buf[op_loc[op]] == '+'){
					dp[left][right][MAX] = max(dp[left][right][MAX],dp[left_left][left_right][MAX]+dp[right_left][right_right][MAX]);
					dp[left][right][MIN] = min(dp[left][right][MIN],dp[left_left][left_right][MIN]+dp[right_left][right_right][MIN]);
				}else{
					dp[left][right][MAX] = max(dp[left][right][MAX],dp[left_left][left_right][MAX]-dp[right_left][right_right][MIN]);
					dp[left][right][MIN] = min(dp[left][right][MIN],dp[left_left][left_right][MIN]-dp[right_left][right_right][MAX]);
				}
			}
		}
	}

	printf("%d\n",dp[0][num_count-1][MAX]);

	return 0;
}

