#include <bits/stdc++.h>
using namespace std;
int main() {
  long long tc = 1, n, a = 0, b, c, d, i;
  vector<long long> v, v1;
  string s, ss;
  while (tc--) {
    cin >> s;
    for (int i = 0; i < s.size(); i++) {
      if (s[i] != 'a') {
        a++;
        s[i] = s[i] - 1;
        if (s[i + 1] == 'a') break;
      }
    }
    if (a == 0) s[s.size() - 1] = 'z';
    cout << s << endl;
  }
  return 0;
}
