#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  string s;
  cin >> s;
  bool k = 0;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'a' && k) break;
    if (s[i] != 'a') s[i] = (s[i] - 1), k = 1;
  }
  if (!k) {
    int num = s.back() - 'a';
    num--;
    num += 26;
    num %= 26;
    s[s.size() - 1] = num + 'a';
  }
  cout << s;
  return 0;
}
