#include <bits/stdc++.h>
using namespace std;
static const int INF = 0x3f3f3f3f;
static const long long INFL = 0x3f3f3f3f3f3f3f3fLL;
static const long long MOD = 1000000007;
template <class T>
void DEBUGA(T arr[], T n) {
  for (int i = 0; i < (n); i++) cout << arr[i] << " ";
  cout << "\n";
}
void solve() {
  string S, ans;
  cin >> (S);
  int i = 0;
  while (i < S.length()) {
    if (S[i] != 'a') break;
    if (i == S.length() - 1)
      ans += 'z';
    else
      ans += 'a';
    i++;
  }
  while (i < S.length()) {
    if (S[i] == 'a')
      break;
    else
      ans += S[i] - 1;
    i++;
  }
  while (i < S.length()) ans += S[i++];
  cout << (ans) << "\n";
}
int main() {
  solve();
  return 0;
}
