#include <bits/stdc++.h>
using namespace std;
int a[100000];
int main() {
  string st;
  cin >> st;
  int count = 0;
  for (int i = 0; i < st.length(); i++) {
    if (st[i] == 'a') count++;
  }
  if (count == st.length()) {
    for (int i = 0; i < st.length() - 1; i++) printf("a");
    printf("z");
  } else {
    for (int i = 0; i < st.length(); i++) a[i] = (int)st[i];
    int j = 0;
    while (a[j] == 97 && j < st.length()) {
      printf("a");
      j++;
    }
    while (a[j] != 97 && j < st.length()) {
      printf("%c", (char)(a[j] - 1));
      j++;
    }
    while (j < st.length()) {
      printf("%c", (char)a[j]);
      j++;
    }
  }
  return 0;
}
