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

int main(){
  string s;
  std::cin >> s;
  for (int i = 0; i < s.length(); i++) {
    s[i] = (s[i] - 'A' - (i + 1) + 26*1000)%26 + 'A';
  }
  std::cout << s << std::endl;
  return 0;
}