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