#include <bits/stdc++.h>
using namespace std;
int main() {
  string a;
  cin >> a;
  bool flag = false;
  for (int i = 0; i < a.length(); ++i) {
    while (a[i] != 'a' && i < a.length()) {
      flag = true;
      a[i++]--;
    }
    if (flag) break;
  }
  if (!flag) a[a.length() - 1] = 'z';
  cout << a << endl;
  return 0;
}
