#include <bits/stdc++.h>
using namespace std;
void solve() {
  string s;
  cin >> s;
  if (count(s.begin(), s.end(), 'a') == 0) {
    for (int i = 0; i < s.length(); i++) s[i]--;
  } else if (count(s.begin(), s.end(), 'a') == s.length())
    s[s.length() - 1] = 'z';
  else if (s[0] != 'a') {
    for (int i = 0; i < s.length(); i++) {
      if (s[i] == 'a')
        break;
      else
        s[i]--;
    }
  } else if (s.length() == 1 && s[0] == 'a')
    s[0] = 'z';
  else {
    int index = s.length();
    for (int i = 0; i < s.length(); i++) {
      if (s[i] != 'a') {
        index = i;
        break;
      }
    }
    if (index != s.length()) {
      for (int i = index; i < s.length(); i++) {
        if (s[i] == 'a')
          break;
        else
          s[i]--;
      }
    }
  }
  cout << s << endl;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(nullptr);
  solve();
  return 0;
}
