#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1.0);
const int A = 1234567;
long long arr[A];
int main() {
  string s;
  cin >> s;
  int l = 0;
  while (s[l] == 'a' && l < s.length()) l++;
  if (l == s.length()) {
    s[s.length() - 1] = 'z';
    cout << s;
    return 0;
  }
  while (true) {
    if (s[l] == 'a' || l == s.length())
      break;
    else {
      s[l] -= 1;
      l++;
    }
  }
  cout << s;
  return 0;
}
