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