#include <bits/stdc++.h>
using namespace std;
int ra() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
int main() {
  string ch;
  cin >> ch;
  string old = ch;
  for (int i = 0; i < ch.size(); i++)
    if (ch[i] != 'a') {
      for (int j = i; j < ch.size(); j++) {
        if (ch[j] == 'a')
          break;
        else
          ch[j] = ch[j] - 1;
      }
      break;
    }
  if (ch == old) ch[old.size() - 1] = 'z';
  cout << ch;
  return 0;
}
