#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  bool ChangeDone = 0;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] != 'a') {
      ChangeDone = 1;
      for (int j = i; j < s.length(); j++)
        if (s[j] != 'a')
          s[j] = s[j] - 1;
        else
          break;
    }
    if (ChangeDone) break;
  }
  if (ChangeDone)
    cout << s;
  else {
    s[s.length() - 1] = 'z';
    cout << s;
  }
  return 0;
}
