#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 4;
const int mod = 1e8;
const long long INF = 1e18;
const int inf = 1e9;
int main() {
  ios_base::sync_with_stdio(false), cin.tie(NULL);
  ;
  string s;
  cin >> s;
  bool ok = 0;
  int pos = 0;
  int n = s.size();
  while (!ok && pos < n) {
    for (int i = pos; i < n; ++i) {
      if (s[i] == 'a') break;
      ok = 1;
      s[i] = (char)(s[i] - 1);
    }
    ++pos;
  }
  if (!ok)
    s[s.size() - 1] = (s[s.size() - 1] == 'a' ? 'z' : (char)(s[s.size()] - 1));
  cout << s;
}
