#include <bits/stdc++.h>
using namespace std;
string solve(string &S) {
  bool broken = false;
  if (S.size() == 1) {
    if (S[0] == 'a') {
      S[0] = 'z';
      return S;
    }
    if (S[0] != 'a') {
      S[0] = S[0] - 1;
      return S;
    }
  }
  for (int i = 0; i <= S.size() - 1; ++i) {
    if (S[i] != 'a') {
      S[i] = S[i] - 1;
      broken = true;
    } else if (S[i] == 'a') {
      if (i == S.size() - 1) S[i] == 'z';
      if (broken == true) return S;
      if (i == S.size() - 1) S[i] = 'z';
    }
  }
  return S;
}
int main(int argc, char *argv[]) {
  ios_base::sync_with_stdio(false);
  string S;
  cin >> S;
  cout << solve(S) << endl;
  return 0;
}
