#include <bits/stdc++.h>
using namespace std;
int main(int argc, const char *argv[]) {
  string s;
  cin >> s;
  int h = 0;
  while (s[h] == 'a' && h < (int)s.size() - 1) h++;
  int t = h + 1;
  while (t < (int)s.size() && s[t] != 'a') t++;
  for (int i = h; i < t; i++) {
    if (s[i] == 'a') {
      s[i] = 'z';
    } else {
      s[i]--;
    }
  }
  cout << s << endl;
  return 0;
}
