#include <bits/stdc++.h>
using namespace std;
priority_queue<string, vector<string>, greater<string> > p;
int main() {
  ios_base::sync_with_stdio(0);
  long long int n, m, k;
  string s, tmp;
  cin >> s;
  tmp = s;
  long long int i = 0, ck = 0;
  while (s[i] == 'a' && i < s.length()) i++;
  while (s[i] != 'a' && i < s.length()) {
    s[i++]--;
    ck = 1;
  }
  if (ck == 0) {
    if (s[s.length() - 1] == 'a')
      s[s.length() - 1] = 'z';
    else {
      s[s.length() - 1]--;
    }
  }
  cout << s << endl;
}
