#include <iostream>
using namespace std;

string S;

int main() {
	cin >> S;
	
	for (int i = 0; i < S.size(); i++) {
		int x = S[i] - 'A';
		x -= i + 1;
		while (x < 0) x += 26;
		x %= 26;
		S[i] = 'A' + x;
	}
	
	cout << S << '\n';
	
	return 0;
}