#include<iostream>
#include<string>
#include<stdio.h>

using namespace std;


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