#include <bits/stdc++.h>
using namespace std;
const long double EPS = 1e-9;
const long long MOD = 1000000007;
const long long MAXN = 100010;
int main(void) {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cerr.tie(0);
  string s;
  int maxs = 0, start = -1, i;
  cin >> s;
  for (i = 0; i < s.length(); i++) {
    if (s[i] != 'a' && maxs == 0) {
      start = i;
      maxs++;
    } else if (s[i] != 'a') {
      maxs++;
    } else if (s[i] == 'a' && maxs != 0)
      break;
  }
  if (start == -1 && maxs == 0)
    s[s.length() - 1] = 'z';
  else {
    for (i = start; i < start + maxs; i++) s[i] = s[i] - 1;
  }
  cout << s << '\n';
  return 0;
}
