#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) { return (b == 0 ? a : gcd(b, a % b)); }
long long lcm(long long a, long long b) { return (a * (b / gcd(a, b))); }
bool getbit(int num, int idx) { return (num >> idx & 1) == 1; }
int setbit(int num, int idx, bool val) {
  if (val == true) return (num | (1 << idx));
  return num & ~(1 << idx);
}
int flipbit(int num, int idx) { return num ^ (1 << idx); }
int cntbits(int mask) {
  int res = 0;
  while (mask) mask &= (mask - 1), res++;
  return res;
}
int main() {
  string s;
  cin >> s;
  int idx = 0;
  while (idx < s.length() && s[idx] == 'a') idx++;
  int time = 0;
  for (int i = int(idx); i < int(s.length()); ++i)
    if (s[i] == 'a')
      break;
    else
      s[i]--, time++;
  if (!time && s[s.length() - 1] == 'a')
    s[s.length() - 1] = 'z';
  else if (!time)
    s[s.length() - 1]--;
  cout << s << endl;
  return 0;
}
