#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] == 'a') {
      continue;
    }
    int j = i + 1;
    while (j < s.length() && s[j] != 'a') {
      ++j;
    }
    for (int r = i; r < j; r++) {
      --s[r];
    }
    cout << s << "\n";
    return 0;
  }
  s.back() = 'z';
  cout << s << "\n";
}
