#include <bits/stdc++.h>
using namespace std;
int main() {
  char s[1000005];
  cin >> s;
  int start = 0;
  int i;
  for (i = 0; s[i]; i++) {
    if (s[i] != 'a') {
      start = 1;
      s[i] = s[i] - 1;
    } else {
      if (start == 1 && s[i] == 'a') break;
    }
  }
  if (!start) s[i - 1] = 'z';
  cout << s;
}
