#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int n = s.size();
  int i = 0;
  while (i < n and s[i] == 'a') i++;
  int j = i + 1;
  while (j < n and s[j] != 'a') j++;
  if (i == n)
    s[n - 1] = 'z';
  else
    for (int k = i; k < j; k++) s[k] = (s[k] - 'a' - 1 + 26) % 26 + 'a';
  cout << s << endl;
  return 0;
}
