#include <bits/stdc++.h>
using namespace std;
#define int long long

#define dbg(x...) \
do { \
std::cout << #x << " -> "; \
err(x); \
} while (0)

void err() {
	std::cout << std::endl;
}

template<class T, class... Ts>
void err(T arg, Ts &... args) {
	std::cout << fixed << setprecision(10) << arg << ' ';
	err(args...);
}

void GENSHEN_START() {
	string s;cin >> s;
	int s_size = s.size();
	vector<int>cnt;
	vector<int>col;
	for (int i = 0; i < s_size; ++i) {
		int j = i;
		for (; j < s_size; ++j) {
			if (s[j] != s[i]) break;
		}
		cnt.push_back(j - i);
		if (s[i] == '0') col.push_back(0);
		else col.push_back(1);
		i = j - 1;
	}
	int ans = 1e9;
	int cnt_size,col_size;
	cnt_size = col_size = cnt.size();
	for (int i = 0; i < col_size; ++i) {
		for (int j = i; j < col_size; ++j) {
			if (col[i] == col[j] && col[i] == 1) {
				int sum = 0;
				for (int k = 0; k < cnt_size; ++k) {
					if (k < i && col[k] == 1) sum += cnt[k];
					else if (k >= i && k <= j && col[k] == 0) sum += cnt[k];
					else if (k > j && col[k] == 1) sum += cnt[k];
				}
				ans = min(ans,sum);
			}
		}
	}
	int one_size = 0,zero_size = 0;
	for (int i = 0; i < cnt_size; ++i) {
		if (col[i] == 0) {
			zero_size += cnt[i];
		}
		else {
			one_size += cnt[i];
		}
	}
	ans = min(ans,s_size - one_size);
	ans = min(ans,s_size - zero_size);
	cout << ans;
	return ;
}

signed main() {
	ios::sync_with_stdio(false);cin.tie(nullptr);
	int T = 1;
	//cin >> T;
	while (T--) GENSHEN_START();
	return 0;
}