#include <bits/stdc++.h>
using namespace std;

int main(){
  string S;
  cin>>S;
  for(int i=0;i<S.length();i++){
    if(S.at(i)-(i+1)%26<65){
      cout<<char(S.at(i)-(i+1)%26+26);
    }
    else{
      cout<<char(S.at(i)-(i+1)%26);
    }
  }
  return 0;
}