#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <valarray>
#include <vector>

#define N 1000
#define re(i,n) for(int i=0;i<(n);i++)
#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define fe(i,n,f) for_each(i,n,f)
#define bw(a,b,c) (((a)<=(b))&&((b)<=(c)))
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
int main(void){
	string s;
	cin>>s;
	re(i,s.size()){
		s[i]=(((s[i]-'A')-(i+1))%26);
		if(s[i]<0)s[i]=26+s[i];
		s[i]+='A';
	}
	cout<<s<<endl;
	return 0;
}