#include <bits/stdc++.h>
using namespace std;
 
int main(){
  string S;
  cin >> S;
  vector<int>ascii(S.size());
  
  for(int i=0; i<S.size(); i++){
      ascii.at(i)=int (S.at(i)-'A')-(i+1)%26;
      if(ascii.at(i)<0) ascii.at(i)+=26;
  }
  
  for(int i=0; i<S.size(); i++){
      ascii.at(i)+='A';
      S.at(i)=char (ascii.at(i));
      cout << S.at(i);
  }
  return 0;
}