using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;

namespace AtCoder.Contest.A
{
	static class Program
	{
		public static void Main(string[] args)
		{
			var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
			Console.SetOut(sw);

			var cin = new Scanner();

			string s = cin.Next();
			var q = new Queue<string>();
			int x = 0;
			int y = 0;
			bool hasFilledX = false;
			bool isInBlacket = false;
			bool isNextPlus = false;
            for (int i = 0; i < s.Length; i++)
            {
				if (s[i] == '(') isInBlacket = true;
				else if (s[i] == ')')
				{
					if (isNextPlus) q.Enqueue((x + y).ToString());
					else q.Enqueue((x - y).ToString());

					isInBlacket = false;
				}
				else if (!isInBlacket) q.Enqueue(s[i].ToString());
				else
				{
					if (s[i] == '+') isNextPlus = true;
					else if (s[i] == '-') isNextPlus = false;
					else if (hasFilledX) y = s[i] - '0';
					else
					{
						x = s[i] - '0';
						hasFilledX = true;
					}
				}
            }

			int ans = 0;
			isNextPlus = true;
            foreach (var e in q)
            {
				if (e == "+") isNextPlus = true;
				else if (e == "-") isNextPlus = false;
                else
                {
					if (isNextPlus) ans += int.Parse(e);
					else ans -= int.Parse(e);
                }
            }
            Console.WriteLine(ans);

			Console.Out.Flush();
		}
	}

	class Scanner
	{
		string[] s;
		int i;

		char[] cs = new char[] { ' ' };

		public Scanner()
		{
			s = new string[0];
			i = 0;
		}

		public string Next()
		{
			if (i < s.Length) return s[i++];
			string st = Console.ReadLine();
			while (st == "") st = Console.ReadLine();
			s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
			if (s.Length == 0) return Next();
			i = 0;
			return s[i++];
		}

		public int NextInt()
		{
			return int.Parse(Next());
		}

		public int[] ArrayInt(int N, int add = 0)
		{
			int[] Array = new int[N];
			for (int i = 0; i < N; i++)
			{
				Array[i] = NextInt() + add;
			}
			return Array;
		}

		public long NextLong()
		{
			return long.Parse(Next());
		}

		public long[] ArrayLong(int N, long add = 0)
		{
			long[] Array = new long[N];
			for (int i = 0; i < N; i++)
			{
				Array[i] = NextLong() + add;
			}
			return Array;
		}

		public double NextDouble()
		{
			return double.Parse(Next());
		}

		public double[] ArrayDouble(int N, double add = 0)
		{
			double[] Array = new double[N];
			for (int i = 0; i < N; i++)
			{
				Array[i] = NextDouble() + add;
			}
			return Array;
		}
	}
}