#include <bits/stdc++.h>
using namespace std;
char s[100005];
int main() {
  cin >> s;
  int n = strlen(s);
  bool not_started = true, finished = false;
  for (int i = 0; i < n; i++) {
    if (s[i] == 'a' && i < n - 1 && not_started) continue;
    if (s[i] == 'a' && i == n - 1 && not_started) {
      s[i] = 'z';
      continue;
    }
    if (s[i] != 'a' && !finished) {
      not_started = false;
      s[i]--;
      continue;
    }
    if (s[i] == 'a') {
      finished = true;
    }
  }
  cout << s << endl;
}
