#include <bits/stdc++.h>
using namespace std;
int main(void) {
  string s;
  cin >> s;
  int e = 0;
  for (long long i = 0; i < s.length(); i++) {
    if (s[i] != 'a') {
      e = 1;
      while (s[i] != 'a' && i < s.length()) {
        s[i] = s[i] - 1;
        i++;
      }
      break;
    }
  }
  if (e == 0) s[s.length() - 1] = 'z';
  cout << s;
  return 0;
}
