#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
const long long inf = 1e16;
const long long ninf = LLONG_MIN;
const long double eps = 1e-12;
const long long N = 1000005;
const long long LOGN = 19;
const long double PI = 3.14159265358979323846;
string s;
int main() {
  ios_base::sync_with_stdio(0);
  cin >> s;
  long long n = s.size();
  long long is = 1;
  for (int i = 0; i < n; i++) {
    if (s[i] != 'a') is = 0;
  }
  if (is) {
    for (int i = 0; i < n - 1; i++) cout << "a";
    cout << "z\n";
    return 0;
  }
  if (s[0] == 'a') {
    long long i = 0;
    while (s[i] == 'a' && i < n) {
      cout << s[i];
      i++;
    }
    long long la = n;
    for (int j = i; j <= n - 1; j++) {
      if (s[j] == 'a') {
        la = j;
        break;
      }
      cout << (char)(s[j] - 1);
    }
    for (int i = la; i <= n - 1; i++) cout << s[i];
    cout << "\n";
  } else {
    long long la = -1;
    for (int i = 0; i < n; i++) {
      if (s[i] == 'a') {
        la = i;
        break;
      }
    }
    if (la == -1) {
      for (int i = 0; i < n; i++) {
        cout << (char)(s[i] - 1);
      }
      cout << "\n";
      return 0;
    } else {
      for (int i = 0; i < la; i++) {
        cout << (char)(s[i] - 1);
      }
      for (int i = la; i <= n - 1; i++) {
        cout << s[i];
      }
      cout << "\n";
      return 0;
    }
  }
  return 0;
}
