#include <bits/stdc++.h>
using namespace std;
int main() {
  char str[100005];
  cin >> str;
  int flag = 0, i;
  char checkString[100005];
  for (i = 0; str[i] != '\0'; i++) {
    checkString[i] = 'a';
  }
  checkString[i] = '\0';
  if (strcmp(str, checkString) == 0) {
    checkString[strlen(checkString) - 1] = 'z';
    cout << checkString;
  } else {
    for (i = 0; str[i] != '\0'; i++) {
      if (!flag && str[i] == 'a') continue;
      if (flag && str[i] == 'a')
        break;
      else {
        flag = 1;
        str[i]--;
      }
    }
    cout << str;
  }
}
