#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int counter = 0;
  int changed = 0;
  bool goIn = true;
  int a = 0;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'a') a++;
  }
  if (a == s.size()) {
    s[s.size() - 1] = 'z';
    cout << s;
    goIn = false;
  }
  if (goIn) {
    for (int i = 0; i < s.size(); i++) {
      if (s[i] == 'a' && s.size() > 1) {
        switch (changed) {
          case 0:
            counter++;
            changed = 1;
            break;
          case 2:
            counter = 2;
        }
      } else if (s[i] != 'a' && counter != 0) {
        s[i]--;
        changed = 2;
      } else if (s[i] != 'a' && counter == 0) {
        s[i]--;
        counter++;
        changed = 2;
      }
      if (counter == 2) break;
    }
  }
  if (goIn) {
    cout << s;
  }
}
