#include <bits/stdc++.h>
using namespace std;
long long int gcd(long long int a, long long int b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
bool isPrime(int n) {
  if (n <= 1) return false;
  if (n <= 3) return true;
  if (n % 2 == 0 || n % 3 == 0) return false;
  for (int i = 5; i * i <= n; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
void ghost() {
  long long int n, i, j, q = 0, k, l, x = 0, y = 0, z, m;
  string s, p;
  cin >> s;
  l = s.size();
  for (long long int i = 0; i < l; i++) {
    if (s[i] == 'a') x++;
  }
  for (long long int i = 0; i < l; i++) {
    if (s[i] != 'a') {
      s[i] = s[i] - 1;
      y = 1;
    } else if (y == 1 && s[i] == 'a')
      break;
  }
  if (x == l) {
    s[l - 1] = s[l - 1] + 25;
  }
  cout << s;
}
signed main() {
  long long int test = 1;
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  while (test--) ghost();
  return 0;
}
