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

int main()
{
    string str1;
    char str2[1025];

    cin >> str1;
    for(int i=0; i<str1.length(); i++){
        str2[i] = 'A' + (str1[i] - 'A' - ((i + 1)%26));
        if(str2[i] < 'A'){
            str2[i] = 26 + str2[i];
        }
    }
    str2[str1.length()] = '\0';
    cout << str2 << endl;

    return 0;
}