#include <bits/stdc++.h>
using namespace std;
char a[100005];
int flag = 0, k, b = 0;
int main() {
  cin >> a;
  int n = strlen(a);
  if (n == 1 && a[0] == 'a')
    cout << "z";
  else {
    for (int i = 0; i < n; i++) {
      if (a[i] == 'a') {
        k = i;
        b = 1;
        break;
      }
    }
    if (b) {
      if (k > 0) {
        for (int i = 0; i < k; i++) {
          if (a[i] != 'a') {
            a[i] = a[i] - 1;
            flag = 1;
          } else if (a[i] == 'a' && flag)
            break;
        }
      } else if (k == 0)
        for (int i = 1; i < n; i++) {
          if (a[i] != 'a') {
            a[i] = a[i] - 1;
            flag = 1;
          } else if (a[i] == 'a' && flag)
            break;
          else
            continue;
        }
      if (flag == 0) a[n - 1] = 'z';
    } else {
      for (int i = 0; i < n; i++) a[i] = a[i] - 1;
    }
    for (int i = 0; i < n; i++) cout << a[i];
  }
  return 0;
}
