#include <bits/stdc++.h>
using namespace std;
string s;
int lo = -1, hi = -1, l;
int main() {
  cin >> s;
  l = s.length();
  for (int i = 0; i < l; i++) {
    if (s[i] != 'a') {
      lo = i;
      break;
    }
  }
  if (lo == -1) lo = l - 1;
  for (int i = lo; i < l; i++) {
    if (s[i] == 'a') {
      hi = max(lo, i - 1);
      break;
    }
  }
  if (hi == -1) hi = l - 1;
  for (int i = lo; i <= hi; i++) {
    if (s[i] != 'a')
      s[i]--;
    else
      s[i] = 'z';
  }
  cout << s << endl;
  return 0;
}
