#include <bits/stdc++.h>
using namespace std;
int main() {
  char a[100005], b[100005];
  cin >> a;
  int lena = strlen(a);
  int i = 0, j;
  for (int i = 0; i < lena; i++) {
    b[i] = a[i];
  }
  while (i < lena && a[i] == 'a') i++;
  while (i < lena && a[i] != 'a') {
    b[i] = a[i] - 1;
    i++;
  }
  if (strcmp(a, b) == 0) {
    b[lena - 1] = 'z';
  }
  cout << b << endl;
  return 0;
}
