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