#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  string s;
  cin >> s;
  int pos1 = -1, pos2 = s.size() - 1;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] != 'a') {
      pos1 = i;
      break;
    }
  }
  for (int i = pos1 + 1; i < s.size(); i++) {
    if (s[i] == 'a') {
      pos2 = i - 1;
      break;
    }
  }
  if (pos1 == -1) {
    s.pop_back();
    s.push_back('z');
    return cout << s, 0;
  }
  for (int i = pos1; i <= pos2; i++) {
    s[i] -= 1;
  }
  cout << s;
}
