#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int a;
  bool notflip = true;
  bool flipping = false;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] != 'a' && notflip) {
      notflip = false;
      flipping = true;
    } else if (s[i] == 'a' && !notflip) {
      flipping = false;
    }
    if (flipping) {
      a = s[i] - 'a';
      a += 25;
      a %= 26;
      s[i] = 'a' + a;
    }
  }
  if (notflip) {
    a = s[s.length() - 1] - 'a';
    a += 25;
    a %= 26;
    s[s.length() - 1] = 'a' + a;
  }
  cout << s;
}
