Night at the museum

#include<iostream>
#include<vector>
#include<algorithm>
#include<cctype>


using namespace std;



int main (){
    string s;
    cin>>s;


      int current = 'a';
    int total = 0;


    for(auto ch : s){
   int clock = abs(current - ch);
   int anti = 26 - clock;
      total += min(clock,anti);
     current = ch;

        
    }

    cout<<total;

  


    return 0;
}