#include <algorithm>
#include <iostream>
#include <string>

using namespace::std;

int main(void){
	
	string str;
	cin >> str;

	for(int i=0; i<str.size();++i){
		str[i] = ((str[i] - 'A') - (i+1)%26 + 26 )%26 + 'A';
	}
	cout << str << endl;

	return 0;
}