#include <iostream>
#include <string>

using namespace std;


char decode(char c, int n){
    n = n % 26;
    int cn = c - 'A';
    cn = cn - n;
    cn = cn % 26;
    if(cn < 0){
        return 'Z' - cn;
    }else{
        return 'A' + cn;
    }
}


int main(){
    string S;
    cin >> S;
    for(int i = 0; i < S.size(); i++){
        S[i] = decode(S[i], i+1);
    }

    cout << S << endl;


    return 0;
}