#include <bits/stdc++.h>
using namespace std;
string s;
int main() {
  int i;
  while (cin >> s) {
    int flag = 0;
    for (i = 0; i < s.length(); i++)
      if (s[i] != 'a') break;
    int j = 0;
    for (j = i; j < s.length(); j++) {
      if (s[j] == 'a') break;
      s[j]--;
      flag = 1;
    }
    if (i == s.length()) s[i - 1] = 'z';
    cout << s << endl;
    s[0] = '\0';
  }
}
