#include <bits/stdc++.h>
using namespace std;
char s[100009];
int main() {
  int l, i, c, m, n;
  cin >> s;
  l = strlen(s);
  for (i = 0, c = 0; i < l; i++) {
    if (s[i] == 'a') c++;
  }
  if (c == 0) {
    for (i = 0; i < l; i++) s[i] = s[i] - 1;
  } else {
    for (i = 0, m = 0, n = 0; i < l; i++) {
      if (s[i] != 'a') {
        m = 1;
        s[i] = s[i] - 1;
        n++;
      } else if (m == 1 && s[i] == 'a')
        break;
    }
  }
  if (n == 0) s[l - 1] = 'z';
  cout << s << endl;
  return 0;
}
