#include <bits/stdc++.h>

using namespace std;

class Solution
{
    public:
    vector<bool> state;

    Solution()
    {
        char tmp;

        while(cin >> tmp)
        {
            if(tmp == '+')
                state.push_back(true);
            else
                state.push_back(false);
        }


    }

    void reverse( size_t start, size_t end ){
        vector<bool> tmp;
        tmp.clear();

        // cout << start << " " << end << endl;

        while(end >= start)
        {
            tmp.emplace_back(state[end]);
            end--;
        }

        // cout << "reversed this shit: "<< endl;
        // for(auto j : tmp)
        // {
        //     cout << j;
        // }
        // cout << endl;

        for(auto j : tmp)
        {
            state[start] = j;
            start++;
        }
    }


    size_t solve()
    {
        size_t operations = 0;
        size_t i = 0;
        bool prev = !state[i];

        while( i < state.size() ){
            // cout << "===========" << endl;
            // cout << "i is: " << i << endl;
            if( state[i] == prev){
                // cout << "found match on: " << i << endl;
                // print();
                operations++;

                size_t startIndex;
                size_t endIndex;

                startIndex = i;

                while( state[i] == prev ) i++;

                while( state[i] != prev ){
                    prev = state[i];
                    i++;
                    if( i >= state.size() ) break;
                }

                endIndex = i - 1;
                reverse( startIndex, endIndex);
                i = 0;
                prev = !state[0];
            }
            
            prev = state[i];
            i++;
        }

        return operations;
    }

    void print(){
        for( auto it : state ){
            cout << it;
        }
        cout << endl;
    }
};

signed main()
{
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    Solution sol;

    cout << sol.solve() << endl;
    return 0;
}