#include <iostream>
#include <string>
using namespace std;
int main()
{
	string a;
	getline(cin, a);
	int num = 0;
	int sum = 0;
	for (int i = 0; i < a.size(); i++)
	{
		if (a[i] >= 48 && a[i] <= 57)
		{
			num = num * 10 + a[i]-48;
		}
		if (a[i] == '+')//遇到加号的时候进行结算
		{
			sum += num;
			num = 0;
//while循环可以将符号后面紧跟着的一个数进行读取并加减
			while (a[i+1] >= 48 && a[i+1] <= 57)
			{
				num = num * 10 + a[i+1] - 48;
				i++;
			}
			sum += num;
			num = 0;
		}
		if (a[i] == '-')
		{
			sum -= num;
			num = 0;
			while (a[i + 1] >= 48 && a[i + 1] <= 57)
			{
				num = num * 10 + a[i + 1] - 48;
				i++;
			}
			sum -= num;
			num = 0;
		}
	}
	cout << sum;
	return 0;
}