#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int n = s.size();
  int flag = 0;
  if (s[0] == 'a') {
    for (int i = 1; i < n; i++) {
      if (s[i] != 'a' && flag == 0) flag = 1;
      if (flag == 1) {
        if (s[i] == 'a') break;
        s[i] = s[i] - 1;
      }
    }
  } else {
    for (int i = 0; i < n; i++) {
      if (s[i] == 'a') break;
      s[i] = s[i] - 1;
      flag = 1;
    }
  }
  if (flag == 0) {
    s[n - 1] = 'z';
  }
  cout << s << "\n";
  return 0;
}
