import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Journals {


    static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

    static int group1 = 0; // +-
    static int group2 = 0; // -+

    public static void main(String[] args) throws IOException {

        char[] line = reader.readLine().toCharArray();

        int last = 0;

        for (int i = 0; i < line.length; i+=2) {

            char p = line[i];
//            char d = line[i+1];

            if (p == '+') {
                if (last == 2) {
                    group2++;
                }
                last = 1;
            } else {
                if (last == 1) {
                    group1++;
                }
                last = 2;
            }

        }

        if (last == 1) {
            group1++;
        } else {
            group2++;
        }

        System.out.println(Math.min(group1, group2));


    }

}