#include <bits/stdc++.h>
using namespace std;
const int INF = 1 << 28;
const long long MOD = 1000000007;
const int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  string s;
  cin >> s;
  int cnt = 0;
  bool flg = false;
  for (int i = 0; i < (int)s.size(); i++) {
    if (s[i] == 'a') {
      if (flg) break;
    } else {
      s[i]--;
      flg = true;
    }
  }
  if (!flg) s[s.size() - 1] = 'z';
  cout << s << endl;
  return 0;
}
