import java.io.*;
import java.util.*;

/**
 * You Win (aka Western Union), ACM ICPC SER 2013 (02.nov.2013)
 *
 * @author john brodie
 * 
 */
public class YouWin_jbrodie {

   private static final int MAX = 20;
   private static int[][] memo = new int[1<<MAX][MAX];

   private static char[] word;

   private static void initMemo() {
      for(int i = 0; i < 1<<MAX; ++i) {
         for(int j = 0; j < MAX; ++j) {
            memo[i][j] = 0;
         }
      }
   }

   private static int rotate(char from, char to) {
      int result = Math.min( ((from-to)+26) % 26, ((to-from)+26) % 26 );
      // System.err.format("rotate:from=%c,to=%c,result=%d%n",from,to,result);
      return result;
   }


   // count the cost of printing in position `next` when we have just
   // printed in the `last` position.
   //
   // when moving to the right, e.g. next > last, count the number of
   // 1's in our mask between last and next (not including the one at
   // last).
   //
   // when moving to the left, e.g. next < last, count the number of
   // 1's between and this time include the one at last.
   private static int position(int mask, int last, int next) {
      int count = 0;
      int from, to;
      if( next < last ) {
         for(int i = next; i <= last; ++i) {
            if( (mask & (1<<i)) != 0 ) count += 1;
         }
      } else {
         for(int i = last+1; i <= next; ++i) {
            if( (mask & (1<<i)) != 0 ) count += 1;
         }
      }
      // System.err.format("pos:mask=%d,last=%d,next=%d,count=%d%n",
      //                   mask,last,next,count);
      return count;
   }

   private static int solve(int mask, int last) {
      // System.err.format("solve:mask=%d,last=%d%n",mask,last);
      if( memo[mask][last] == 0 ) {
         memo[mask][last] = Integer.MAX_VALUE;
         int newMask = mask ^ (1<<last);
         for(int i = 0; i < word.length; ++i) {
            if( (newMask & (1<<i)) != 0 ) {
               int progress =
                  solve(newMask,i)
                  + position(newMask,i,last)
                  + rotate(word[i],word[last]) + 1;
               memo[mask][last] = Math.min(memo[mask][last],progress);
            }
         }
      }
      int result = memo[mask][last];
      //System.err.format("solve:mask=%d,last=%d,result=%d%n",mask,last,result);
      return result;
         
   }

   public static void main(String [] args) {

      Scanner in = new Scanner(System.in);
      while( in.hasNextLine() ) {
         String s = in.nextLine();
         if( "0".equals(s) ) break;
         word = s.toCharArray();
         initMemo();
         for(int i = 0; i < word.length; ++i) {
            memo[1<<i][i] = rotate('A',word[i])+1;
         }
         int allOnes = 0;
         for(int i = 0; i < word.length; ++i) {
            allOnes |= 1 << i;
         }
         int answer = Integer.MAX_VALUE;
         for(int i = 0; i < word.length; ++i) {
            answer = Math.min(answer,solve(allOnes,i));
         }
         System.out.format("%d%n", answer);
      }
      System.out.close();
   }

}