#include <bits/stdc++.h>
using namespace std;
const long long int mod = 1000000007;
void solve() {
  string c;
  cin >> c;
  if (*max_element((c).begin(), (c).end()) ==
          *min_element((c).begin(), (c).end()) &&
      *max_element((c).begin(), (c).end()) == 'a') {
    for (int i = 0; i < c.length() - 1; ++i) {
      cout << 'a';
    }
    cout << 'z';
    return;
  }
  int i = 0;
  while (i < c.length() && c[i] == 'a') i++;
  while (i < c.length() && c[i] != 'a') {
    c[i] = char(c[i] - 1);
    i++;
  }
  cout << c;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  solve();
}
