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