#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  return b == 0 ? a : gcd(b, a % b);
}
int arr[1000005];
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  string a;
  cin >> a;
  int len = a.length();
  int flag = 0;
  for (int i = 0; i < len; i++) {
    if (a[i] != 'a') {
      a[i] = a[i] - 1;
      flag = 1;
    } else if (flag == 1 && a[i] == 'a') {
      break;
    }
  }
  if (flag == 0) a[a.length() - 1] = 'z';
  cout << a << "\n";
  return 0;
}
