#include <bits/stdc++.h>
using namespace std;
int main() {
  char s[100005];
  scanf("%s", s);
  int l = strlen(s);
  int i;
  int count = 0;
  int f = 0;
  for (i = 0; i < l; i++) {
    if (s[i] == 'a')
      count++;
    else if (s[i] != 'a' && f == 0) {
      s[i] = s[i] - 1;
      if (s[i + 1] == 'a') f = 1;
    }
  }
  if (count == l) {
    s[l - 1] = 'z';
  }
  printf("%s\n", s);
  return 0;
}
