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