#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  while (cin >> s) {
    int st = 0;
    while (st < s.length() && s[st] == 'a') st++;
    bool f = false;
    for (; st < s.length(); st++) {
      if (s[st] == 'a') break;
      s[st]--;
      f = true;
    }
    if (!f) s[s.length() - 1] = 'z';
    cout << s << endl;
  }
  return 0;
}
