#include<iostream>
#include<string>
#include<algorithm>
                       //ABCDEFGHIJKLMNOPQRSTUVWXYZ
const std::string alp = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

auto index(const char c){
    auto it = std::find(alp.begin(), alp.end(),c);
    return std::distance(alp.begin(), it);
} 

using ui = unsigned int;
int main(){
    
    std::string s;
    std::cin >> s;
    
    for(decltype(s.size()) i{}; i<s.size(); ++i){
//        std::cout << i<<"\n";
        const ui v = index(s[i]);
//        std::cout << v<<"\n";
        const ui x = (i+1) % alp.size();//移動量
        
        //復号後のalphabet index
        ui decoded = v>=x ? v-x : v+alp.size()-x;
        /*if(decoded != 25)
            std::cout <<alp[v]<<" "<< v <<" "<< x <<"\n";
        */
//        std::cout <<i<<" "<< x <<" "<< v<<" "<<(v+alp.size())-x<<" "<< decoded <<" ";
        std::cout << alp[decoded];
//        std::cout << "\n";
    }
    std::cout <<"\n";
    return 0;
}