#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  string S;
  cin >> S;
  int N = S.size();
  int pos = -1;
  for (int i = 0; i < N; i++) {
    if (S[i] != 'a') {
      pos = i;
      break;
    }
  }
  if (pos == -1) {
    S[N - 1] = 'z';
  } else {
    for (int i = pos; i < N; i++) {
      if (S[i] == 'a') break;
      int c = S[i] - 'a';
      c--;
      if (c < 0) c += 26;
      S[i] = 'a' + c;
    }
  }
  cout << S << endl;
  return 0;
}
