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

int main(){
    string S;
    cin >> S;

    for(int i=0;i<S.size();i++) {
        if(S[i]-((i+1)%26)>'A'-1) S[i]-=((i+1)%26);
        else S[i]=S[i]-((i+1)%26)+26;
    }

    cout << S << endl;

    return 0;
}