#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, i, flag = 0;
  string s;
  cin >> s;
  n = s.length();
  for (i = 0; i < n; i++) {
    if (s[i] == 'a') {
    } else {
      flag = 1;
      while (s[i] != 'a' && i < n) {
        s[i] = s[i] - 1;
        i++;
      }
      break;
    }
  }
  if (flag == 0) s[n - 1] = 'z';
  cout << s;
}
