//
// Created by cteam001 on 11/5/22.
//
#include <bits/stdc++.h>

using ll = long long;
using namespace std;

int main(){
    char a, b;
    char last = ' ';
    ll plus = 0, minus = 0;

    while(true)
    {
        a = getchar();
        if(a=='\n')
            break;
        b = getchar();
        if(a == '+')
        {
            if(last != ' ' && last != a){
                if(last == '+')
                    ++plus;
                else
                    ++minus;
            }
            last = a;
        }
        else{
            if(last != ' ' && last != a){
                if(last == '+')
                    ++plus;
                else
                    ++minus;
            }
            last = a;
        }
    }
    if(last == '+')
        ++plus;
    else
        ++minus;
    cout << (plus < minus ? plus : minus) << endl;

    return 0;
}