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