#include <bits/stdc++.h>
using namespace std;
int main() {
  int t, n, i, j;
  string s;
  while (cin >> s) {
    n = s.length();
    int f = 0;
    for (int i = 0; i < n; i++) {
      if (s[i] != 'a') {
        s[i]--;
        f = 1;
        for (int j = i + 1; j < n; j++) {
          if (s[j] != 'a')
            s[j]--;
          else
            break;
        }
        break;
      }
    }
    if (f == 0) s[n - 1] = 'z';
    cout << s << "\n";
  }
  return 0;
}
