#include <iostream>

using namespace std;

int main()
{
    int k, i, ints[3], sig;
    ints[1] = ints[2] = 0;
    char a, b;
    string s;
    cin >> s;
    k = s.size() / 2;
    int sign = 0;
    for (i = 0; i < k; i++) {
        a = s[2 * i];
        b = s[2 * i + 1];
        if (a == '+') sig = 1;
        else sig = 2;
        if (sig != sign) ints[sig]++;
        sign = sig;
    }
    if (ints[1] + ints[2] == 1) cout << 0 << endl;
    else cout << min(ints[1], ints[2]) << endl;
}