#include <bits/stdc++.h>
const int MAXN = 110000;
char s[MAXN];
int main() {
  scanf("%s", s);
  for (int i = 0; s[i]; i++)
    if (s[i] != 'a' || !s[i + 1]) {
      s[i] = (s[i] - 'a' + 25) % 26 + 'a';
      for (int j = i + 1; s[j] && s[j] != 'a'; j++) s[j]--;
      break;
    }
  puts(s);
  return 0;
}
