#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int f = 0;
  int ct = 0;
  for (int i = 0; i < s.size(); i++) {
    if (f == 0 && s[i] == 'a') {
      ct++;
    } else if (f <= 1 && s[i] != 'a') {
      s[i] = s[i] - 1;
      f = 1;
    } else if (f == 1 && s[i] == 'a') {
      f = 2;
    }
  }
  if (ct == s.size()) {
    int b = s.size() - 1;
    s[b] = 'z';
  }
  cout << s;
  return 0;
}
