#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <map>
#include <set>
#include <cstdio>
#include <cmath>
#define rep(i,l,n) for(lint i=l;i<n;i++)
#define rer(i,l,n) for(lint i=l;i<=n;i++)
#define all(a) a.begin(),a.end()
#define o(a) cout<<a<<endl
#define pb(a) push_back(a)
#define mk(a,b) make_pair(a,b)
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef vector<int> vi;
typedef vector<lint> vli;
typedef vector<vi> vvi;
typedef pair<int,int> pii;

char solve(char c,int k){
	char res;
	int x=c-'A'-k;
	while(x<0){
		x+=26;
	}
	return 'A'+x;
}

int main(){
	string s,ans;
	cin>>s;
	rep(i,0,s.size()){
		ans+=solve(s[i],i+1);
	}
	o(ans);
}