#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9;
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  for (int i = int(0); i < int(4); ++i) {
    if (s[i] == '+')
      n++;
    else
      n--;
  }
  cout << n << endl;
  return 0;
}
