#include <bits/stdc++.h>
using namespace std;
FILE *stm;
const double PI = 22.0 / 7.0;
const long long MXN = 1e5 + 1;
const long long MNN = 1e3 + 1;
const long long MOD = 1e9 + 7;
const long long INF = 1e18;
bool srt(string a, string b) { return a.size() > b.size(); }
int gcd(int a, int b) {
  if (b == 0)
    return a;
  else
    gcd(b, a % b);
}
int lcm(int a, int b) { return (b / gcd(a, b)) * a; }
int main() {
  string first;
  cin >> first;
  int n = first.size();
  int ctr = 0;
  int j = 0;
  while (first[j] == 'a' and j < n) {
    ctr++;
    j++;
  }
  if (ctr == n) {
    first[n - 1] = 'z';
  } else if (first[0] != 'a') {
    for (int i = 0; i < n and first[i] != 'a'; i++) first[i] = first[i] - 1;
  } else if (first[0] == 'a') {
    int i = 0;
    while (first[i] == 'a') {
      i++;
    }
    for (; i < n and first[i] != 'a'; i++) first[i] = first[i] - 1;
  }
  cout << first << endl;
  return 0;
}
