#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
char s[110000];
int n;
int main() {
  scanf("%s", s + 1);
  n = strlen(s + 1);
  bool bo = 0;
  for (int i = 1; i <= n; i++)
    if (s[i] != 'a') {
      int j = i;
      bo = 1;
      while (j <= n && s[j] != 'a') {
        s[j]--;
        j++;
      }
      break;
    }
  if (bo == 0) s[n] = 'z';
  printf("%s\n", s + 1);
  return 0;
}
