#include <bits/stdc++.h>
using namespace std;
int dX[] = {-1, 0, 1, 0, -1, 1, 1, -1};
int dY[] = {0, 1, 0, -1, 1, 1, -1, -1};
int main() {
  string a;
  bool modified = false;
  cin >> a;
  for (int i = 0; i < a.size(); ++i) {
    if (a[i] != 'a') {
      modified = true;
      for (int j = i; j < a.size(); ++j) {
        if (a[j] == 'a') break;
        a[j] = (char)(a[j] - 1);
      }
    }
    if (modified) break;
  }
  if (!modified) a[a.size() - 1] = 'z';
  cout << a << endl;
  return 0;
}
