#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <utility>

using namespace std;

int main(void){

    string s;
    cin >> s;
    for(int i = 0; i < s.size(); i++){
        int l = i + 1;
        l %= 26;
        int c = (int)(s[i] - 'A');
        c -= l;
        if(c < 0) c += 26;
        s[i] = (char)('A' + c);
    }
    cout << s << endl;

    return 0;
}