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