#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  cin >> s;
  bool done = false;
  for (int i = 0; i < s.size(); i++) {
    if (!done) {
      if (s[i] == 'a')
        continue;
      else
        done = true;
    }
    if (s[i] == 'a') break;
    int x = s[i];
    x--;
    s[i] = (char)x;
  }
  if (!done) s[s.size() - 1] = 'z';
  cout << s << endl;
}
