import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Youwin_artur {

  static final int MAXN = 21;
  static final int[][] dp = new int[1 << MAXN][MAXN];
  static final int[][] rotation = new int[MAXN][MAXN];

  static int n;
  static char[] a;

  public static void main(String[] args) throws Exception {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

    String s;
    while (!"0".equals(s = in.readLine())) {
      n = s.length();
      a = s.toCharArray();

      for (int i = 0; i < n; i++)
        for (int j = 0; j <= i; j++)
          rotation[i][j] = rotation[j][i] = Math.min(Math.abs(a[i] - a[j]), 26 - Math.abs(a[i] - a[j]));

      for (int j = 0; j < 1 << n; j++)
        for (int i = 0; i < n; i++)
          dp[j][i] = 0;
      for (int i = 0; i < n; i++)
        dp[1 << i][i] = Math.min(a[i] - 'A', 26 - a[i] + 'A') + 1;

      int best = Integer.MAX_VALUE;
      for (int i = 0; i < n; i++)
        best = Math.min(best, dp(i, (1 << n) - 1));
      System.out.println(best);
    }
  }

  static int dp(int cur, int mask) {
    if (dp[mask][cur] > 0)
      return dp[mask][cur];
    if (mask == 0)
      return 0;

    int count = 0;
    for (int i = 0; i <= cur; i++)
      if ((mask & (1 << i)) > 0)
        count++;

    int best = Integer.MAX_VALUE;
    int newmask = mask & ~(1 << cur);
    for (int i = 0, j = 0; i < n; i++)
      if ((mask & (1 << i)) > 0) {
        j++;
        if (i == cur)
          continue;
        int translation = j > count ? j - count : count - j - 1;
        best = Math.min(best, dp(i, newmask) + translation + rotation[i][cur] + 1);
        // best = Math.min(best, dp(i, newmask) + translate(newmask, i, cur) + rotation[i][cur] + 1);
      }

    return dp[mask][cur] = best;
  }

  // static int translate(int mask, int i, int j) {
  // if (i < j)
  // mask = (mask >> (i + 1)) & ((1 << (j - i - 1)) - 1);
  // else
  // mask = (mask >> (j + 1)) & ((1 << (i - j)) - 1);
  //
  // mask = mask - ((mask >> 1) & 0x55555555);
  // mask = (mask & 0x33333333) + ((mask >> 2) & 0x33333333);
  // return (((mask + (mask >> 4)) & 0x0F0F0F0F) * 0x01010101) >> 24;
  // }
}