#include<bits/stdc++.h>
using namespace std;
int main(){
    string S; cin >> S;
    for(int i = 0; i < S.size(); i++){
        int key = (S[i] - 'A') - (i + 1);
        while(key < 0) key += 26;
        S[i] = 'A' + key;
        cout << S[i];
    }
    cout << endl;
        
    return 0;
}