#include <bits/stdc++.h>
using namespace std;
string str;
void funk(int x) {
  char ch;
  int i, j, a, b, n;
  n = str.size();
  for (i = x; i < n; i++) {
    if (str[i] != 'a') {
      a = str[i] - 1;
      ch = a;
      str[i] = a;
    } else
      return;
  }
  return;
}
int main() {
  ios::sync_with_stdio(false);
  int i, j, x, y, n, m, a, b, c, d;
  cin >> str;
  n = str.size();
  for (i = 0; i < n; i++) {
    if (str[i] != 'a') {
      funk(i);
      break;
    } else if (i == n - 1) {
      str[i] = 'z';
    }
  }
  cout << str;
  return 0;
}
