#include <iostream>
#include <algorithm>
#include <vector>
#include <string>

unsigned int flipCnt(std::string& input) {
    auto s = input.begin();
    unsigned int flipCnt = 0u;

    while (s != input.end()) {
        char last = *s;
        char curr = *(++s);
        bool found = false;

        while (s != input.end()) {
            if (curr == last) {
                found = true;
                break;
            }

            last = curr;
            curr = *(++s);
        }

        if (!found)
            break;

        char matched = curr;
        char toFind = (matched == '+') ? '-' : '+';

        auto e = s;

        last = *e;
        curr = *(++e);

        while (e != input.end()) {
            if (curr == last && curr == toFind)
                break;

            last = curr;
            curr = *(++e);
        }

        std::reverse(s, e);
        ++flipCnt;
    }

    return flipCnt;
}

int main() {
    std::string input;
    std::cin >> input;
    std::cout << flipCnt(input) << std::endl;
    return 0;
}