#include<iostream>
#include<string>
using namespace std;

int main(){
  string str;
  cin>>str;
  for(int i=0;i<str.size();i++){
    str[i]-='A';
    cout<<char((str[i]-(i+1)%26+26)%26+'A');
  }
  cout<<endl;
  return 0;
}