#include <bits/stdc++.h>
using namespace std;
char s[100001];
int main(int argc, char* argv[]) {
  cin >> s;
  char* p = s;
  for (; *p; ++p) {
    if (*p != 'a') break;
  }
  if (*p == 0) --p;
  if (*p == 'a')
    *p = 'z';
  else
    --*p;
  for (++p; *p && *p != 'a'; ++p) --*p;
  cout << s << endl;
  return 0;
}
