#include <iostream>
#include <string>

using namespace std;

int same_unit(char c) {
    char top = ' ', bot;
    cin >> top >> bot;
    return top == '+';
}

int main() {

    string line;
    getline(cin, line);

    int positives = 0;
    int negatives = 0;
    for (int i = 2; i < (int) line.size(); i += 2) {
        if (line[i] == line[i-1]) {
            if (line[i] == '+')
                positives++;
            else
                negatives++;
        }
    }

    std::cout << (positives > negatives ? positives : negatives) << std::endl;
    return 0;
}