#include <bits/stdc++.h>
using namespace std;
int main() {
  char str[100000];
  char ch;
  int k = 0, i = 0, f = 0, n = 0;
  ch = getchar();
  while (ch != '\n') {
    if (f == 0) {
      if (ch == 'a') {
        if (k == 0) {
          str[i] = ch;
        }
        if (k > 0) {
          str[i] = ch;
          f = 1;
        }
        n++;
      } else {
        str[i] = ch - 1;
        k++;
      }
    } else {
      str[i] = ch;
    }
    if (i == 0) {
    } else {
      cout << str[i - 1];
    }
    i++;
    ch = getchar();
  }
  if (i == n) {
    cout << 'z';
  } else {
    cout << str[i - 1];
  }
  return 0;
}
