#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5;
char s[maxn];
bool Check(char s[]) {
  for (int i = 0; i < strlen(s); i++)
    if (s[i] != 'a') return false;
  return true;
}
int main() {
  cin >> s;
  if (Check(s))
    s[strlen(s) - 1] = 'z';
  else {
    for (int i = 0; i < strlen(s); i++)
      if (s[i] != 'a') {
        int p = i;
        while (s[p] != 'a' && p < strlen(s)) p++;
        for (int j = i; j < p; j++)
          if (s[j] == 'a')
            s[j] = 'z';
          else
            s[j]--;
        break;
      }
  }
  cout << s << endl;
  return 0;
}
