#include <iostream>
#include <string>
using namespace std;

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

    for(int i = 0; i < s.length(); i++){
        s[i] -= (i + 1) % 26;
        if(s[i] < 'A')
            s[i] += 26;
    }

    cout << s << endl;

    return 0;
}