#include <bits/stdc++.h>
using namespace std;
int main() {
  char s[100005];
  scanf("%s", s);
  int len = strlen(s);
  int t = 0;
  if (s[0] == 'a') {
    if (len == 1) {
      cout << "z";
      return 0;
    }
    int i = 0;
    int ok = 0;
    while (s[i] == 'a') {
      cout << "a";
      i++;
      if (i == len - 1 && s[i] == 'a') {
        cout << "z";
        ok = 1;
        break;
      }
    }
    if (ok == 1) return 0;
    for (; i < len; i++) {
      if (t == 0) {
        if (s[i] == 'a') {
          printf("a");
          t = 1;
        } else
          printf("%c", s[i] - 1);
      } else
        printf("%c", s[i]);
    }
  } else {
    for (int i = 0; i < len; i++) {
      if (t == 0) {
        if (s[i] == 'a') {
          printf("a");
          t = 1;
        } else
          printf("%c", s[i] - 1);
      } else
        printf("%c", s[i]);
    }
  }
  return 0;
}
