#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
template <class T, class U>
inline T tmin(T a, U b) {
  return (a < b) ? a : b;
}
template <class T, class U>
inline T tmax(T a, U b) {
  return (a > b) ? a : b;
}
template <class T, class U>
inline void amax(T &a, U b) {
  if (b > a) a = b;
}
template <class T, class U>
inline void amin(T &a, U b) {
  if (b < a) a = b;
}
template <class T>
inline T tabs(T a) {
  return (a > 0) ? a : -a;
}
template <class T>
T gcd(T a, T b) {
  while (b != 0) {
    T c = a;
    a = b;
    b = c % b;
  }
  return a;
}
int main(int argc, char *argv[]) {
  ios_base::sync_with_stdio(false);
  string s;
  cin >> s;
  int st = s.size(), en = s.size();
  for (size_t i = 0; i < s.size(); i++) {
    if (s[i] != 'a') {
      st = i;
      break;
    }
  }
  for (size_t i = st; i < s.size(); i++) {
    if (s[i] == 'a') {
      en = i;
      break;
    }
  }
  if (st < en) {
    for (size_t i = st; i < en; i++) {
      s[i] -= 1;
    }
  } else {
    s[s.size() - 1] = 'z';
  }
  cout << s << endl;
  return 0;
}
