#include<iostream>

#include<stack>

#include<string>

using namespace std;

char compare(char tp, char op)

{

	if (((tp == '+' || tp == '-') && (op == '*' || op == '/')) || (tp == '#'))

		return '<';

	return '>';

}

int compute(int n1, int n2, char op)

{

	if (op == '+')

		return n1 + n2;

	else if (op == '-')

		return n1 - n2;

	else if (op == '*')

		return n1*n2;

	else if (op == '/')

		return n2 / n1;

}

int main()

{

	stack<char>num;

	stack<char>oper;

	oper.push('#');

	string s;

	cin >> s;

	for (int i = 0; i<s.length(); i++)

	{

		if (s[i] == '0' || s[i] == '1' || s[i] == '2' || s[i] == '3' || s[i] == '4' || s[i] == '5' || s[i] == '6' || s[i] == '7' || s[i] == '8' || s[i] == '9')

			num.push(s[i]);

		else

		{

			char comp = compare(oper.top(), s[i]);

			if (comp == '<')

				oper.push(s[i]);

			else if (comp == '>')

			{

				int num1 = num.top()-'0';

				num.pop();

				int num2 = num.top()-'0';

				num.pop();

				int result = compute(num1, num2, oper.top());

				num.push(result+'0');

				oper.pop();

				oper.push(s[i]);

			}

		}

	}

	if (num.size() != 1)

	{

		while (oper.top() != '#')

		{

			int num1 = num.top()-'0';

			num.pop();

			int num2 = num.top()-'0';

			num.pop();

			int result = compute(num1, num2, oper.top());

			num.push(result+'0');

			oper.pop();

		}

	}

	cout << num.top() << endl;

	return 0;

}