#include <bits/stdc++.h>
using namespace std;
string s;
int main() {
  cin >> s;
  int len = (int)s.size();
  for (int i = 0; i < len; i++) {
    if (s[i] != 'a') {
      int j = i;
      while (j < len - 1 && s[j + 1] != 'a') j++;
      for (int k = i; k <= j; k++) {
        s[k] = char(s[k] - 'a' - 1 + 'a');
      }
      cout << s;
      return 0;
    }
  }
  s[len - 1] = 'z';
  cout << s;
  return 0;
}
