#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <map>
#include <queue>
#include <math.h>

#define pairi pair <int,int>
#define pairll pair <long long,long long>
#define vi vector <int> 
#define vll vector <long long> 
#define mapi map <int,int> 
#define mapill map <int,long long> 
#define seti set <int> 
#define setll set <long long> 
#define pb push_back
#define fr(i,a,b) for(int i = a ; i < b ; i++)
#define fir(i,a,b) for(int i = b ; i >= a ; i--)
typedef long long ll ;


using namespace std;

int main()
{
    int t , n , i , k , *a ;
    string s ;
    cin >> s ;
    n = s.length() ;
    map <char,int> ch ;
    for(char c : s)
        ch[c]++ ;
    int temp = 10000000 ;
    for(auto x : ch)
    {
        int ans = 0 ;
        for(auto m : ch)
            ans += abs(x . first - (m.first)) * (m.second) ;
        temp = min(temp,ans) ;
    }
    cout << temp << endl ;
}