#include <bits/stdc++.h>
using namespace std;
char s[100001];
int main() {
  cin >> s;
  int len = (int)strlen(s);
  int a0 = 0;
  while (a0 < len && s[a0] == 'a') a0++;
  int a1 = a0;
  while (a1 < len && s[a1] != 'a') a1++;
  if (a0 == len)
    s[len - 1] = 'z';
  else
    for (int i = a0; i < a1; i++) s[i] = s[i] - 1;
  puts(s);
  return 0;
}
