#include <bits/stdc++.h>
using namespace std;
void enter(vector<long long int> &ar) {
  long long int n = ar.size();
  for (long long int i = 0; i < n; i++) {
    cin >> ar[i];
  }
}
void show(vector<long long int> &a) {
  long long int n = a.size();
  for (long long int i = 0; i < n; i++) {
    cout << a[i] << " ";
  }
  cout << "\n";
}
void SieveOfEratosthenes(int n, vector<long long int> &pri) {
  vector<bool> prime(n + 1, true);
  for (int p = 2; p * p <= n; p++) {
    if (prime[p] == true) {
      pri.push_back(p);
      for (int i = p * p; i <= n; i += p) prime[i] = false;
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  string s;
  cin >> s;
  long long int n = s.size();
  long long int i;
  for (i = 0; i < n; i++) {
    if (s[i] != 'a') {
      break;
    }
  }
  bool shift_performed = false;
  for (; i < n; i++) {
    if (s[i] != 'a') {
      s[i] = s[i] - 1;
      shift_performed = true;
    } else {
      shift_performed = true;
      break;
    }
  }
  if (!shift_performed) {
    s[n - 1] = 'z';
  }
  cout << s << "\n";
  return 0;
}
