#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  string x;
  cin >> x;
  string y = x;
  for (int i = 0; i < x.length(); i++) {
    if (x[i] == 'a') continue;
    for (int j = i; j < x.length(); j++) {
      if (x[j] == 'a') break;
      x[j] = char(int(x[j]) - 1);
    }
    break;
  }
  if (y == x) {
    x[x.length() - 1] = 'z';
  }
  cout << x << '\n';
  return 0;
}
