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

int main()
{
	string S;
	cin >> S;

	vector<int> tmp;
	bool flag = false;
	while (!S.empty())
	{
		if (S[0] == '*')
		{
			flag = false;
			S.erase(S.begin(), S.begin() + 1);
		}
		else if (S[0] == '+')
		{
			flag = true;
			S.erase(S.begin(), S.begin() + 1);
		}
		else
		{
			string s = "";
			while (!S.empty() && S[0] != '*' && S[0] != '+')
			{
				s += S[0];
				S.erase(S.begin(), S.begin() + 1);
			}
			tmp.push_back(stoi(s));

			if (tmp.size() == 2)
			{
				if (flag)
					tmp[0] = tmp[0] * tmp[1];
				else
					tmp[0] = tmp[0] + tmp[1];
				tmp.pop_back();
			}
		}
	}

	cout << tmp[0] << endl;


	return 0;
}