C

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

int main() {

    string s;
    cin >> s;

    int ans = (int) s.size();

    for (int i = 1; i < (int) s.size(); i++){
        string s1 = "", s2 = "";
        for (int j = 0; j < (int) s.size(); j++){
            if (j < i){
                s1 += s[j];
            } else {
                s2 += s[j];
            }
        }
        map<char, int> m1, m2;
        for (char c1 : s1){
            m1[c1]++;
        }
        for (char c2 : s2){
            m2[c2]++;
        }
        int res = 0;
        for (auto a : m1){
            if (m2.find(a.first) == m2.end()){
                res += a.second;
            }
        }
        for (auto b : m2){
            if (m1.find(b.first) == m1.end()){
                res += b.second;
            }
        }
        ans = min(ans, res);
    }
    cout << ans << endl;

}