#include <iostream>
using namespace std;

int main(void){
  int key = 1;
  char c;
  
  while (cin >> c){
    c -= 'A';
    c = c-key+26;
    c %= 26;
    cout << (char)(c+'A');
    key = (key+1)%26;
  }
  cout << endl;
  return 0;
}