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