#include<bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
typedef long long ll;
using namespace std;
typedef pair<int,int> pii;

const int mod=998244353;
inline int add(int x,int y){int ret=x+y;if(ret>=mod)ret-=mod;return ret;}
inline int sub(int x,int y){int ret=x-y;if(ret<0)ret+=mod;return ret;}
inline int mul(int x,int y){return ((ll)x*y)%mod;}
inline int step(int base,int pw){int ret=1;while(pw){if(pw&1)ret=mul(ret,base);base=mul(base,base);pw>>=1;}return ret;}
inline int invv(int x){return step(x,mod-2);}


const int maxn=3e5+10;



int main(){

    ///freopen("test.txt","r",stdin);

    string s;
    cin>>s;
    vector<pii>vect;
    vect.pb({s[0]-'0',1});
    int n=s.size();
    for(int i=1;i<n;i++){
        if(s[i]-'0'==vect.back().ff)vect[vect.size()-1].ss++;
        else vect.pb({s[i]-'0',1});
    }

    int rez=n;
    for(int i=0;i<(int)vect.size();i++){
        for(int j=i-1;j<(int)vect.size();j++){

            int sum=0;
            for(int k=0;k<vect.size();k++){
                if(k<i || k>j){
                    if(vect[k].ff==1)sum+=vect[k].ss;
                }
                else{
                    if(vect[k].ff==0)sum+=vect[k].ss;
                }
            }

            rez=min(rez,sum);

        }
    }
    printf("%d\n",rez);

    return 0;
}