// No.49 算数の宿題
#include <iostream>
#include <string>
#include <vector>
#include <cctype>
using namespace std;

int main() {
    string S;
    cin >> S;
    vector<int> num;
    vector<char> op;
    int now = 0;
    for (auto c: S) {
        if (isdigit(c)) {
            now = 10 * now + (int)(c - '0');
        } else {
            op.push_back(c);
            num.push_back(now);
            now = 0;
        }
    }
    num.push_back(now);
    while (op.size()) {
        int a = *num.begin();
        int b = *(next(num.begin()));
        char o = *op.begin();
        num.erase(num.begin());
        num.erase(num.begin());
        op.erase(op.begin());
        if (o == '*') num.insert(num.begin(), a + b);
        else num.insert(num.begin(), a * b);
    }
    cout << num[0] << endl;
}