#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  bool ok = 0;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == 'a') continue;
    ok = 1;
    for (int j = i; j < s.size(); j++) {
      if (s[j] == 'a') goto here;
      s[j] = s[j] - 1;
    }
    break;
  }
here:;
  if (!ok) {
    s[s.size() - 1] = 'z';
  }
  cout << s << endl;
  return 0;
}
