#include <bits/stdc++.h>
using namespace std;
int main() {
  int ind;
  string X;
  cin >> X;
  for (int A = 0; A < X.size(); A++) {
    if (X[A] != 'a' || A == X.size() - 1) {
      ind = A;
      break;
    }
  }
  for (int B = 0; B < X.size(); B++) {
    if (B > ind && X[B] == 'a') ind = INT_MAX;
    if (B < ind)
      cout << X[B];
    else {
      if (X[B] == 'a')
        cout << "z";
      else
        cout << (char)(X[B] - 1);
    }
  }
  return 0;
}
