#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
using namespace std;


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