#include <bits/stdc++.h>
using namespace std;
void afify() {
  ios::sync_with_stdio(0);
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
const long long oo = (long long)10e9 + 7;
const double EPS = 1e-4;
int main() {
  afify();
  string s;
  cin >> s;
  bool test = 0;
  for (int i = int(0); i < s.length(); i++) {
    if (s[i] == 'a') {
      if (test == 1) break;
    } else {
      s[i] = s[i] - 1;
      test = 1;
    }
  }
  if (!test) {
    s[s.length() - 1] = 'z';
  }
  cout << s << endl;
  return 0;
}
