#include <bits/stdc++.h>
using namespace std;
long long ans = 1e18;
vector<char> ops;
void solve(vector<long long> a, int pos) {
  if (pos == 3) {
    ans = min(ans, a[0]);
    return;
  }
  for (int i = 0; i < (int)(a).size(); ++i) {
    for (int j = i + 1; j < (int)(a).size(); ++j) {
      long long val = a[i];
      if (ops[pos] == '*') {
        val *= a[j];
      } else {
        val += a[j];
      }
      vector<long long> b;
      for (int k = 0; k < (int)(a).size(); ++k) {
        if (i == k || j == k) {
          continue;
        }
        b.push_back(a[k]);
      }
      b.push_back(val);
      solve(b, pos + 1);
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  vector<long long> a(4);
  for (int i = 0; i < 4; ++i) {
    cin >> a[i];
  }
  for (int i = 0; i < 3; ++i) {
    char c;
    cin >> c;
    ops.push_back(c);
  }
  solve(a, 0);
  cout << ans << "\n";
}
