#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  string s;
  cin >> s;
  int n = s.size();
  int l, r;
  bool flag = false;
  for (auto i : s) {
    flag |= (i != 'a');
  }
  if (!flag) {
    s.back() = 'z';
    cout << s;
    return 0;
  }
  for (l = 0; s[l] == 'a' && l < n; ++l)
    ;
  for (r = l; s[r] != 'a' && r < n; ++r)
    ;
  for (int i = l; i < r; ++i) {
    if (s[i] == 'a')
      s[i] = 'z';
    else
      s[i] = char(s[i] - 1);
  }
  cout << s;
}
