#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  int n = s.length();
  bool shift = 0, cshift = 0;
  for (int i = 0; i < n; i++) {
    if (shift) {
      if (!cshift) {
        if (s[i] == 'a')
          cshift = 1;
        else
          s[i] = (26 + s[i] - 'a' - 1) % 26 + 'a';
      }
    } else {
      if (s[i] != 'a' || i == n - 1) {
        shift = 1;
        s[i] = (26 + s[i] - 'a' - 1) % 26 + 'a';
      }
    }
  }
  cout << s << endl;
  return 0;
}
