#include <bits/stdc++.h>
using namespace std;
char to[255];
char s[100011];
int main() {
  for (int i = 'b'; i <= 'z'; i++) to[i] = i - 1;
  to['a'] = 'z';
  scanf("%s", s);
  int len = strlen(s);
  int cnt = 0;
  for (int i = 0; i < len; i++) {
    if (s[i] == 'a') cnt++;
  }
  if (cnt == len) {
    s[len - 1] = to[s[len - 1]];
  } else {
    for (int i = 0; i < len; i++) {
      if (s[i] != 'a') {
        int j = i;
        while (s[j] != 'a' && j < len) {
          s[j] = to[s[j]];
          j++;
        }
        break;
      }
    }
  }
  puts(s);
}
